There's no question the new engine tech. is much better but that's another video it's amazing when you talk about a certain engines IE: BBC how many people jump on the comment section and feel the need to convince everyone that anything that is old is a waste of time. Yes the new engines of today do make more power for their size. and the engine management system is much better, however this video is about the iron BBC heads, never ounce did I say these heads are better than new technology so please CALM DOWN! if you want to compare new tech to old ummm make a video of your own
My point is that most of the good thicker castings are gone. They are a rarity now. Your video video's are rehashing material from a Petersen Publishing HP book from 30 years ago. Although you are verbally describing the BB Chevy heads characteristics, You are reiterating David Vizard and the other authors stuff.. They are experts. Those authors did your research and made the effort. You are appearing to be BB Chevy god to a younger "lack of knowledge" crowd. Maybe those HP authors should be flattered at your imitation. Or sue....... To the younger guys, my advice......Buy a set of aftermarket new iron heads for the early Mark IV BB Chevy. Or cough up extra $$$ for aluminum street heads. They are not worn out, and possibly angle milled and thin, and you will be $$$ ahead. 90% of Chevrolet castings after 1976 are thin wall castings for low compression and have poor resistance to cracking at exhaust seat area, Panic-mode now by wholesale warehouses loaded down with shelves of old school parts. To make old school work you will spend four thousand dollars for electronic throttle body injector by Edelbrock, Holley + MSD otherwise you will be continually fighting detonation with the old school stuff. No variable valve timing and no detonation sensors in the block. No automatic fuel re-calibration by the ecu for stupid blends of 15% ethanol approved by Obummer. Town to town travel in old iron block is questionable unless you enjoy filling part of trunk with octane booster. A Ford, Chevy, or Dodge V-8 made in the 21st century can live with 9 psi boost on 92 octane pump gas and not have it's owner screwing with timing curve every time he hears rattle in the block at fill up time. I am 50+ years old, and prefer driving instead of buying/installing short blocks that can't live on modern fuel. And the new blocks/heads get 40% better mileage with higher power and lower weight. All the SEMA guys make the good stuff for the modern stuff too. Old block/heads = Ragged edge of destruction. Good at oiling down main-street. .
What those people also dont understand is MONEY. Yeah, the lastest and greatest does make more power, at the same time its alot more expensive. Even nowadays and older setup can make modern horsepower figures often for alot less cash.
Bone Daddy The new LS1 Chevy is the most popular swap engine today. The new small block. I have a new December 2014 issue of Mopar Action and it's also got another hot trend-Disc brake conversions for older cars. The old sheet metal styling of 60's- 70's era cars is cool but most need new quarter panels, or floor pans welded in after 40 years of rust. It's easy to dump 15-20K into an old car. Someone recently did a Dyno test of the $80,000? Hellcat Challenger SRT. It was laying down HP numbers over 722, not the factory advertised 707 HP. Eight speed auto with A/C, Sat/Nav, WiFi, plus room for four. The Hellcat uses a Layton type supercharger. The nice thing about modern muscle[Camaro,Mustang] is that it's now everywhere instead of only at swap meets and now a rarity. I can get parts at a dealer. Buy a road racer like the Shelby or new Camaro. The 2016 Ford H.O. V8 is gonna have a 180 degree flat crank like a NASCAR V8. The new Camaro SS is starting to turn corners like a Porsche. Don't stay in the past: It's like bringing a flintlock to a machine gun war.
I'm looking at a 57 Bel Air with a 454 and a 3 speed tomorrow. Your video has a lot of useful information. I love this, but I have no idea what I'm doing and I'm almost 100% lone wolf in this.
I would avoid the closed chamber heads all together they had big time shrouding issues with the cylinders and chambers, none of them really worked very well as far as factory heads go for the street 049 or 781 is what you want run em with bigger valves and a dome piston and you have an easy 500+ HP
I will be rebuilding my first Chevy big block RV 454. I have own plenty of Chevy small blocks throughout the years. The heads that came on the RV 454 are 045. What can you tell me about these heads? The engine will be used only for street use, no racing. The motor will be going in a 1970 Chevy Nova with a 700r4 transmission with a 2200 stall converter and 373 10 bolt rear end. The only thing I will be installing on the motor is a Comp Cam 274 with springs, locks and retainers, may be bigger valves depending on what it comes with. Any info would be appreciated, thanks.
very nice video with some good info i have a 85 c-30 with a excellent 454 its an old ambulance tons of heavy duty parts and its a dually i want to pull the engine but i have no idea what to do with it just too many options
will schuck They are somewhat average truck heads, pretty good all around performance. If you want better performance- especially higher rpm- you want heads with numbers starting with 38, 39, and 62. There are many specific versions, but the above stated first numbers will be better than the later heads with 33, 34, 35.
hey i think it was a typo cause i have a 1977 454 and i just looked at my heads and there the same number as yours with 2 inch oval ports and i also looked for 366781 and that casting number is not in the gm castings theres a 336781 and thats the only 781 that start in 3 so id say your in the clear
Just curious, I have 781 heads on a 489, I had them put 2.19/1.88s in them at the machine shop. Is that the more popular valve size or would more people use the 2.25s? Also, can having too large a valve actually have a negative effect on performance or is it all down to port flow?
my neighbor has a 1972 monte carlo with the 402 . 66.000 original miles.. car is in excellent shape.. he wants 13.900 for it,, its sat in the garage for 12 years.. not sure if its a good deal.
Got a set of 891 on a 477 can you tell me a little about them I believe they are a old pro stock head I know they have rectangular 380 intake runners note these heads are on a race car not street car
BBC is way cheaper to get into compared to LS, BBC doesn't care if it runs fuel injected or carbed, LS is built in such a way that expensive aftermarket intake manifolds are necessary in order to just install a carburetor. a lot more BBC stock available too, LS just isn't cheap enough for an intermediate enthusiast to start building. Also for towing purposes and good traction in the snow, the extra weight in a pickup truck from the cast iron BBC is going to help keep the front end tires pressed down, the LS is going to be too light to haul heavy loads, and won't have near the stroke torque these things can output.
Midnight Mechanic the manifold to carb a ls1 is expensive because it has to flow a lot you can get cheap manifold but they don't flow that's why ls1 is so popular because 350 hp 350 tq stock a lot of big blocks make torque but hp lacks 430 tq 190 hp runs out really quick
@@utahcountypicazospage5412 they never made a big block with 190 lowest at there worst was 230 and a cam change headers intake and good ignition puts them up to 400hp.
For oval ports the 781 and 049 castings are the best iron oval ports that Chevy came out with. With big valves and a mild port job they actually perform quite well.
@@douglasadams6024 your comment makes no sense. Car Craft did an engine build with TRW flat tops in a .030 over 454 with 781 heads and a flat tappet hydraulic cam and the combo put out 425hp and over 500 ft/lbs of torque. I have basically the same engine and in my Impala it ripped for a heavy car and 8 to 1 compression. It all depends on what you are trying to achieve.
1970 454 LS5 engines were rated at 365hp and LS6 engines were 450hp. The reason for the 402 in 1970 was emissions. Engines larger than 400ci had less restrictive emission standards and big block chevy's were NOT good with passing emissions. Therefore all 396's became 402's The 396 badges were marketing since the SS396 had become a legend.... and SS402 just didn't have that magic.
I know the emmissions issue was to do with the closed chambered head, it was horrible on combustion strength, so yeah that open chamber head along with the bigger bore was their solution.
True, but the 366 is a GREAT source for forged 396/427 crankshafts!! Because of the heavier truck pistons, the counterweighting on them is perfect to use them to build a 396 or 427.
kctransplant70 Agreed we used to buy them from the farmers where I grew up they would just buy a new 366 for their trucks and lay the worn out one out by the barn we could usually pick em up for 50 bucks
if you think an LS 6.0 liter truck engine is a stump puller, clearly you have never driven and have no clue what a 454 is capable of, or a 396 for that matter
Love those peanut ports! I have had lots of big block street cars and the 236 heads are by far the best heads for torqe and throttle response! My budget 454 just went 11.60s with 236 peanut ports.
Those heads are not peanut ports. Lot of misconception about the bbc heads. There are 3 types. Rectangle-oval- and late model small oval peanut ports. I have those 236 heads also.
And I agree with you. People are bench talking. Using larger volume heads to gain a few more horsepower at the expense of losing torque and response is going against the grain. With that fast velocity you can still run a long duration cam and keep your vacuum response.
@@antilaw9911 exactly! I had a flat top 454 with 781s and a xe268 cam and it might have been just as fast or faster as my peanut port street motors I’ve had but in a truck or a heavy car with 3.08 gears and a tight converter those big ovals felt a lot slower down low (where 90% of my driving was) I will admit though with the right cam,gears and converter the big ovals will make more power and be faster at the track!
Good video. I was hoping you would've covered the early closed chamber heads. How do they flow vs. the open chamber head? I've heard a lot of different opinions.
My first bbc .30 over 454 had oval port, closed chamber big valve heads it made enormous amounts of torque, also done extensive port matching, it ran very well. Great video!
I had just built a peanut port head build, has a very mild hydraulic cam, 10.5:1 comp with a torker 2 intake, 2 inch spacer and demon 850 carb That motor in a full interior 78 z28 with a cage and 4.11 gears ran 12.9 at 104 mph, really impressive motor
The mystery motor was the MARK III 427. A "Porcupine style" canted valve design. Quickly protested in NASCAR by competitors it disappeared for three years until a block showed up again as the MARK IV Turbo-Jet 427. 1963's Mark III- Deck height/rod length= Mystery. After Pontiac ceased producing their own V-8 in, I believe 1979-1980? They had some of their idle head designers churn out a few sets of Big Chief cylinder heads for the Chevrolet Mark IV. These may qualify as factory for restricted class racing. If you find a pair of those, buy them. They will out-do any factory iron 60's style head that the best port/weld skilled shop could turn out and many modern aftermarket alloy CAD designs too. The pinnacle of the factory cam in block- tall deck Mark IV head. Oldsmobile produced a limited quantity of factory webbed girdle alloy V-8 blocks in the early to mid 80's. Aimed at Drag/ Pro-Street types. Capable of displacements of 700 cubic inches just add the Big Chief Poncho Heads. Factory cam in block Mark IV V-8's became legend on Woodward Avenue-Take No Prisoners. Again, a very rare Chevy BB Variant.
A couple of corrections: The 496/8.1 was sold new up to 2010 as a motorhome engine for the Workhorse chassis. It should also be noted that the 496 is a LOW RPM motor. Red line is 4800 rpm, and you do not want to exceed that. Its a great low rpm motor, but not good to scream it for HP. The crate 502 is much better for that. Second thing to point out about heads. Fast burn heads are tons more efficient. The combustion chamber is much tighter around the plug area. The most efficient time to push on the piston is at 14 degrees ATDC. Energy occurring before that time or after that time is less efficient. Fast burn means the pressure build up occurs within a narrower window, so that more energy is closely timed to occur at 14 degrees after TDC. Not only does this improve efficiency, but in addition, the faster burn reduces the likelihood of detonation. As a result, higher compression ratios can be used on pump gas. 9.1 on 87 octane. 11.7 on 93 octane.
You are exactly right about 427’s and oval port heads. I have a 427 in my 1966 Chevelle and I surprised an LS6 Chevelle and beat him easily. He sold his 1970 stock SS after that which was a shame. He said “I have rectangular port heads so I should have at least 100 more horsepower than you do!” Wrong! That was in 1983. I still have it and it runs great. I saw him at a grocery store a few months ago and reminded him about it but he said he didn’t remember the race!
Big Block opinions are like assholes, everybody has one! BBC's have so many building options. All that matters is the correct combination of parts to get the motor you want.
Yep, that Factory GM "Mystery Motor" was a very rare, exotic "short stroke/big bore/big block" engine, and something like only 20 of them were ever produced by GM, and distributed to Junior Johnson, who got 6 of em, Smokey Yunick got 6 also, and I forget who else may have got a couple, but I know that NASCAR rules required that ANY new engine HAD TO BE made available to the competitors ( only 1 or 2 motors each ) running Ford & Chrysler, so they could "inspect what they were running against". Junior Johnson immediately bought all the other Mystery Motors BACK from the competitors, except for Smokey Yunick, who kept his 6 motors. That way, Junior Johnson had enough of these motors to last the entire season. IT RAN LIKE A BAT OUT OF HELL. Junior Johnson led EVERY race using them, and if the engine didn't fail, they WON the race, just spanking the competition. But the problem was, the heads were plagued with valve train issues. If it lasted, it DID win the race, plus led the most laps during any race that it won.......if not, it LED the race until it quit running. Of course Johnson & Smokey built these engines to produce what Johnson claimed was around 800 hp, in 1963. There's a video here on youtube showing Junior displaying one of the actual race cars with this mystery motor set up for the big tracks ( Daytona, Charlotte, etc....the Talladega track had not been built yet ), in which the car had some serious innovations itself, in addition to the mystery motor. He stated that "Had the motor held together for every race, THEY WOULD'VE WON EVERY RACE THE ENTIRE SEASON, and he was being dead serious. Look for that video.
Nice video. I have been running BBCs since 1970, when I swapped a 1967, 350 HP Chevelle 396 into a 55 Chev Cameo. The reason I brought this up, is that my heads have the D port, which is D shaped large oval port. I can't remember, but I thought it was a 208 casting. This was a weird engine, in that it has the factory high rise Holley manifold and carb. It is a fantastic street engine. I also have a 68 427 and 2 454 engines. I mention this because, my 435 HP 427 has a heavier piston than the 396 and the 454, which means that it also has a much larger, 8 inch, front balancer. The other thing that you might mention, is that the heads had three, maybe more, different chamber designs, the closed chamber, the partially open chamber, and the full open chamber. I thought this might be important t mention, because the pop up pistons for these different chambers are not a universal fit and caution is advised when mixing and matching heads and pistons. Another thing, I thought was important, was that the 396 and 427 are internally balanced engines, and the 454 is an externally balanced engine. I know you couldn't mention everything in one video, and I did enjoy it. I love these
Lloyd Stolworthy closed chambers shroud the intake valves and decrease flow. You can have the chambers plunge cut to “relieve” the intake valves and get the flow rate up to match the open chamber flow rate.... I have had it done to 66/67 702 CC oval port heads.
@@Myvintageiron7512 listening on your statement on the Rectangular port head not working on the street below 3500 rpm. THAT would suggest they needed an equal length properly sized long tube header to make the work on the street.
Thank you for the very informative vid. I'm not a BBC guy but currently dealing with a boat motor rebuild with a Gen 4 454 and heard about the Rec/Oval ports and didn't know much about it. Now I have a better idea of what's going on. Thanks Again!
IMO the only great improvement in the new engines is fuel injection and coil on plug design. The basic engine have not changed enough to make any real differences. Lets face it folks; a carb engine with a nice came sounds better that an injected engine with the same cam profile - just sayin! BTW there is no substitution for cubic inches. If the block hasn't got enough cubes stuff a huffer on top and over drive it.
You are sorta correct on the Mystery engine. It was more like Gen. 1.5 as it did NOT have a gen II bottom end. It was a block that was closer to the 348/409 blocks in design but modified for the gen II heads. So bottom end was truly a mystery as it was not a 348/409 OR a 396!
Just recently purchased an old K30 Camper special Dually with a 454 in it. Appreciate you taking the time to get novice mechanics like me up to speed on the older specs and differences. Plan on taking your advice on getting torque out of the engine I have and switching the heads to match up with a 750 carb. Not looking to make rediculous power, just good torque for pulling 7-10 tons on a gooseneck.
I am building a 454 from a winnebago as well from 1978. It has the 781 heads on it. I'd say yours are 781s as well. Should make a beast of a pulling engine for you.
I used to build stroker motors out of 427 hi-deck and this was before 502 or 572. Easy to build a 520 and still have thick cylinder walls. 12-71 with alcohol with 300 hp NOS and it would put a smile on anyone face. Unless they were racing you.
I am confused on the 396/402 thing. Your saying GM cast 396 blocks and then bored them .030 before building them to be installed in vehicles? Makes no sense. Are you sure it is not a block cast with a different bore?
!970 EPA rules made a break for engines or 400 CI. Instead of the using the 396 emission standards it was cheaper to bore the motors to 402 and meet the emissions standards with just a carb tuning and PCV.
I have a set of 049 Heads with bigger valves huge port job, 11 to 1 in a 454 .060 over making 632 on the dyno. Running 114 race gas. These heads are so nice. I'm running a Clay Smith solid lifter cam nice power and tons of torque. I really liked your video a lot, very informational, Thanks.
a fuel injected well built 496 big block will respond the same and make more power ALWAYS than a LS(yes even a 454lsx and tittanium rodded lightweight valve 427)
I believe the 396 was available in 1965 with 12.5 compression ratio rated at 425 h.p. They were called the nascar motor and was available as a crate engine to regular consumers . I Knew two racers that each purchased these motors . They were very potent and sounded very badass . Another friend bought a 66 chevelle , if I'm not mistaken , had that very same motor . I think this was called the Mark IV , or Mystery Motor , and some guys , back in the day , called it "The Nascar Motor".
Unfortunately, no stock iron Mark IV head is impressive these days. They weren't impressive 30 years ago when I built my 30 over 1/4" stroke tall deck 454 (489CID/8.0L. 688HP). I went with World Merlins.
Don't forget the ZL-X 427. It was essentially a ZL-1 with an iron block only sold over the counter, not as famous as the LS-7 crate motor, but popular in it's day.
I’d love to see a part two. Thank you very much for the video. It was really informative. This next summer. I’m going to be rebuilding a 454 for a 4 x 4 truck. Are any of the mid 90s 454 heads better than others? Thank you. God bless you and your family. Duane.
Casey Myers first of all check and see what you got for heads. Most likely there going to be a peanut port and you dont want to startout there. But there are many iron oval port heads that will easily make 1hp per cubic inch and you can usually find these heads out there somewhere for sale. Ideally you want an 049 or 781 but 279s and 156s can be worked a little to breath fire as well but porting and valves arent cheap either
Start putting together 5 grand. five hundred dependable horses out of a BBC is easy. stay away from high compression, square port heads unless it is strictly a all out WFO racer..
Thanks for making this video. I have a 454 engine in a Cabin Cruiser style boat that runs in the lower RPM ranges below 4200 and I was thinking of changing from the peanut port heads to the square or oval port. After what you've explained the heads I have seem to be the best to use for the most torque which is what's needed in my type of boat. Very good video, Thanks !
1st off: thank you for responding to a camshaft question I had for you couple years ago. 2nd, I later watched your video about choosing camshafts and it really opened my eyes to the whole cam theory. 3rd and lastly, need your advice yet again on another situation. Just acquired a '68 L78 396 4 bolt main for my 68 Nova. The guy through in a set of 390 (427 heads) and I bought a set of 990 rectangle port heads from him (which were actually on the engine, put on the engine at some time beings that they appear to be '73 year heads). So far from what I've gathered is that the large oval port 427 (390) heads are proven better for daily street type car situations (which is what I intend to use the car for). I don't intend on seriously racing this thing. Just want to give it some more power (the 'ol 267 4.4 is dependable as hell, just ain't cuttin' the mustard in the way of "performance driving pleasure"). Hell, you actually spoke of this in this video as well (power being made at low RPM's). And yeah, I've read it elsewhere too like I mentioned, but I've gotta ask you straight up exclusively because your really the only reputable guy I know (can think of) who really knows his stuff. So, I have to ask. For a every other day driver 68 (4dr at that) Nova, what would you recommend I put on this 396? The 390 oval port heads (which I'm assuming are "large oval port")? Or the 990 "hi perf" rectangle port heads? Very much looking forward to your input on this so that I know how to properly move forward with this project. Thank you for all of the knowledgeable videos you post. They make sense, are easy to understand and really help out folks like myself who lack the knowledge.
John Lingenfelter found that oval ports out-performed rectangular ports by a good margin up to 800+ horse power. On a 454 with about 475 hp with rectangular ports the switch to oval ports added almost 100 hp. On a 496 with 560 hp using rectangular ports he picked up 70 hp switching to oval ports. The oval ports were 049 or 781's with larger valves, a port match and smoothing the short side radius on the intake port. I know most older Chevy guys know this so this is for the younger guys. Don't waste your time on rectangular ports unless you're building a 572 prostock motor turning 8000 rpm's in a 2500lb car. They just aren't good for the average high performance application.
I love it when you guys post good solid information, you are so right the 781/049 heads are killer street/strip heads and they make make mad power I have a few vids where I install the big stainless valves in those heads The most important thing to remember is they are open chamber heads and they have around 120 cc chambers this makes pretty low compression on a 454 you need a .120 dome piston for pump gas for around 10 to 1 more dome for race gas I love these heads I am putting them on my 502 with a .060 dome forged piston
Thank you. I bought a 1970 Corvette in 1995. It had a 454 that wasn't numbers matching and the seller didn't know anything about it except it was supposed to be a 454. Someone had ground the stamped numbers off the front of the block and tried to restamp it as a 1971 LS6? I took it to the dragstrip and it ran good consistent 13.40's-13.50's all summer long. That winter I pulled the intake(a factory GM aluminum) to find rectangular port heads. I then looked up the block and head casting numbers and the date codes and it turned out to be a complete 1970 LS6. I built a set of 049 heads like I read Lingenfelter doing and put them on it with a performer intake and a Crane grid hydraulic cam. My Chevy friends almost cried when they saw what I was doing. "You took the better heads off for a set of smogger oval ports" they would tell me. The next spring at the drag strip I ran a best of 12.21 with consistent 12.30's. Some of my friends shut up and took notice, others still to this day stick to the assumption that I made a mistake. I sold the 291heads in the local paper and a guy restoring an LS6 Chevelle bought them along with the aluminum GM intake. The money I got for that paid for the other parts plus a little cash in my pocket.
You're right Dave the wave. Remember the little over 700 horsepower solid roller big block Chevy blower motor oval irons vs. Square irons. The oval irons won horsepower and torque the square Port irons lost. The average square Port and 990 head had a 325cc runner it didn't flow to good and was too big. And remember when guys took cylinder heads ported and Polished stock heads and hurt the horsepower and torque they Dynod the motor after putting it back together wasted a lot of time and money and then to have less horse power and torque. I guess we've all seen people go to big carburetor intake cylinder heads cam headers and hurt horsepower and torque.
He's wrong about the 396 horsepower ratings. The 396 was introduced in the 1965 Corvette and rated at 425 HP, not 375. The 396 Chevelle came later that year. It was rated at 375 HP. It was the same engine as the Corvette but with a different horsepower rating. Very few 1965 396 Chevelles were built. In 1966 the 396SS Chevelle came into its own still rated at 375 HP.
Donald Smith That's right. The L78 396 (awesome engine!) was rated 425hp in the vette, 375hp in the chevelle and camaro. This might be more legitimate than it seems because of the difference in exhaust manifolds. The corvette had much better flowing exhaust than the others. But, throw a set of headers on any of them and you have a screamer of a big block.
Are you sure about that it was 425 instead of 375 on a 396 I'm a Mopar guy and I'm going to question that I'm building a 67 GTX by the way but just going through the comments Donald that kind of threw me for a little bit of a loophole I get back to me like to pick your brain fellow Gearhead Mopar or no car 67 GTX ragtop for Speed 440 balanced and blueprinted 4:56 gears with a 4-speed
I realize this info is not new I'm just putting it out there most now days don't read they Google it when they want to know something most of what I learned about of engines is from experience quite honesty I have never read those author's you listed either
I'm up in the air between a cadillac 472, buick 455 or building a 454. I'm on a budget and it's going in a Buick 65skylark. I can get all these engines for under 400$. I don't really understand the difference between a screamer and a torque monster and the reason behind why one runs out of power faster. I want something strong, snappy and able to drag race sometimes.. Thanks a lot I always watch your videos and I've seen the 455 ones aswell
IF YOU ONLY HAVE 400 BUCKS FOR A MILL STAY AWAY FROM THE DRAGSTRIP. You will be embarrassed by some 16 year old kid in a Honda civic who has 2 grand in the headwork. BTW THE CADDY IS A TURD except for making a lot of torque. I will give you a grand for the Buick frame if it's a good one.
I put a 455 on my 84 K20, best motor ever for a truck. I never got around to it, but Mondo is a BOP motor specialist place, they make a stroker kit that makes it a 496. Numbers advertised are silly, if I remember right 510lbs torque @ 2800rpm. Awesome stuff lol
Ronnie Buicks u need to go watch the episode of power Block where they show the Defense between all the GM V8 and y the chevrolet V8 small and big block came out on top.
Two decades ago, I had a 454 from a late '70s pickup for my Malibu. I had an Offenhauser rectangular port intake for it. So I port match the heads to the intake not to far to break into the valve spring area, just to give a smooth transition between the intake and heads. I have no clue if ever I had performance gain with this, but the damn car ran great from stop lights to the highway, no issue in throttle response or surging at high rpm (4800 lol) So I wonder if I can do the same thing with my stock tbi 1991 peanut port engine in my K3500, if I ever decide to install a better cam, chip it and put the tbi unit on a performer oval port intake. Just to improve the performance a bit, without altering it's great hauling duties! Thanks for this very informative video! I'm a subsciber now!!
Dude great video I was impressed on the new teachings. For me going to school to be a mechanic I still have a great deal to learn even though my dad is a master ase mechanic. Hey man thanks for taking the time to produce this sort video. Well keep your engines rockin and the tacs a knockin.
A couple more details about big block history: In mid-1965, the first year for the 396, it wasn't just the Corvette and Chevelle that was offered with a 396. The most common 396 was the 325 hp 396 (L35) that was available in the Impala/full size cars. I have one from a 65 Impala SS. It wasn't mentioned, but in 1970, the Chevelle was available with the famous LS6 454, 450hp engine. And a correction: The 1970 LS5 engine wasn't 440 hp. The 70 LS5 was produced in 2 versions, a 360hp(Monte Carlo SS454 and Chevelle SS454) and 390 hp for Corvette and full size Chevrolet. But the 360 and 390 hp engines were basically the same, with ratings measured at different rpm levels. So the output difference was just on paper, so they basically had the same output in reality.
I'm trying to decide witch oval port i had on my 73 c10 454 pickup truck. I had my heads of due to compression failure in a sylinder. Turned out it was a hydraulic lifter that had locked itself at max, so the valve stayed open all the time. Wish i had checked the lifters before i took my heads off :) This is alot of years ago so its hard to say what i had. But i remember i thought back then that the intake ports looked huge.
The LS5 was factory rated at 360 or 390 HP (depending on the source) and 500 lb/ft of torque, NOT 440 hp and 590 lb/ft. They may have actually put out around 440 hp, but 590 lb/feet is WAY optimistic. The LS6 put out 450 rated horsepower (probably closer to 500 actual horsepower) and the same 500 lb/ft of torque as the LS5.
The 502 had the same bore spacing as every other big block at 4.84 inches. GM has never changed the bore spacing, only the aftermarket has. The 1970 LS 5 had 360 hp in the Chevelle and 360 hp in the Corvette, not 440 hp. The LS 6 had 450 and only came in the Chevelle. As far as the rectangular port heads are concerned, they are exactly what you need in a 454 or bigger engine that is expected to turn 6500 and will reward you with sparkling top end power. The oval ports work fine but do not flow enough to feed an engine that is big and/or will have the cam to generate higher rpm and the expected high power up there. Remember that the big blocks, especially the 454 have a short connecting rod and a low rod ratio. This means that the engine can activate a large intake runner and needs enough volume to feed itself. Having the shorter rod generates better low end torque so the effect of too big an intake port is masked. Compare this to a 440 Mopar with it's really tall deck and really long rod. The intake runners are tiny compared to the Chevy square port runner. You can put one runner of a Chevy rect, port intake gasket over both intake ports on the Mopar intake ports. Don't be afraid of the rectangular port heads, the factory created them for a reason and they are the bomb on the right application.
402 also came factory in the Monte Carlo. Also I’m pretty partial to the Gen 6 heads for a street car. They flow pretty good and make good torque on the low end
You should do a video on the best casting #s of the 454 motor. I have been looking to build a 454 and I am confused about which casting is the one to get for the best performance with the 781 heads. Thanks for all of your hard work and awesome info!
There are a few videos floating around about bolting on a set of heads out of the box. Generally, is there a process you go through with a brand new set of castings (assembled/bare)?
I love that you touched on the 402 BBC. In my 1947 Ford truck sits a 1972 402 big block Mark IV LS3. Not going to win many races but it was my father's daily driver. This motor, transmission and carburetor all came right out of the same vehicle together and that's how they will stay. Good stuff :)
Only one discrepancy in this video. You said that the Ls5 was 440hp. Actually you were describing the Ls6,and the rating was 450hp on that particular motor (conservatively). But I have have an awesome set of square port heads that I took off a 461ci because of the low RPM air velocity and people thought I was crazy for saying that I didn't need them on my street driven Chevelle. Enjoyed the video.
great video. as far as what came out and when, people can do there own home work. I understand it's based off your readings and such, either way good job giving us an idea about the bbc heads and a bit of history.
In 1965, the 396 in a Corvette was 425 HP. You could also order a "drag pack" option in a plain jane Biscayne which included a 425 HP 396 and a 4 speed.
There's no question the new engine tech. is much better but that's another video it's amazing when you talk about a certain engines IE: BBC how many people jump on the comment section and feel the need to convince everyone that anything that is old is a waste of time. Yes the new engines of today do make more power for their size. and the engine management system is much better, however this video is about the iron BBC heads, never ounce did I say these heads are better than new technology so please CALM DOWN! if you want to compare new tech to old ummm make a video of your own
My point is that most of the good thicker castings are gone. They are a rarity now. Your video video's are rehashing material from a Petersen Publishing HP book from 30 years ago.
Although you are verbally describing the BB Chevy heads characteristics, You are reiterating David Vizard and the other authors stuff.. They are experts. Those authors did your research and made the effort. You are appearing to be BB Chevy god to a younger "lack of knowledge" crowd. Maybe those HP authors should be flattered at your imitation. Or sue.......
To the younger guys, my advice......Buy a set of aftermarket new iron heads for the early Mark IV BB Chevy. Or cough up extra $$$ for aluminum street heads.
They are not worn out, and possibly angle milled and thin, and you will be $$$ ahead. 90% of Chevrolet castings after 1976 are thin wall castings for low compression and have poor resistance to cracking at exhaust seat area,
Panic-mode now by wholesale warehouses loaded down with shelves of old school parts. To make old school work you will spend four thousand dollars for electronic throttle body injector by Edelbrock, Holley + MSD otherwise you will be continually fighting detonation with the old school stuff. No variable valve timing and no detonation sensors in the block. No automatic fuel re-calibration by the ecu for stupid blends of 15% ethanol approved by Obummer.
Town to town travel in old iron block is questionable unless you enjoy filling part of trunk with octane booster. A Ford, Chevy, or Dodge V-8 made in the 21st century can live with 9 psi boost on 92 octane pump gas and not have it's owner screwing with timing curve every time he hears rattle in the block at fill up time.
I am 50+ years old, and prefer driving instead of buying/installing short blocks that can't live on modern fuel. And the new blocks/heads get 40% better mileage with higher power and lower weight. All the SEMA guys make the good stuff for the modern stuff too.
Old block/heads = Ragged edge of destruction. Good at oiling down main-street.
.
What those people also dont understand is MONEY. Yeah, the lastest and greatest does make more power, at the same time its alot more expensive. Even nowadays and older setup can make modern horsepower figures often for alot less cash.
Bone Daddy Someone fifty years ago said 'Speed costs money, how fast do you want to go?'
I believe the exact quote was "How fast can you afford to go" and it was Smokey yunick who said it
Bone Daddy
The new LS1 Chevy is the most popular swap engine today. The new small block.
I have a new December 2014 issue of Mopar Action and it's also got another hot trend-Disc brake conversions for older cars.
The old sheet metal styling of 60's- 70's era cars is cool but most need new quarter panels, or floor pans welded in after 40 years of rust.
It's easy to dump 15-20K into an old car.
Someone recently did a Dyno test of the $80,000? Hellcat Challenger SRT. It was laying down HP numbers over 722, not the factory advertised 707 HP. Eight speed auto with A/C, Sat/Nav, WiFi, plus room for four.
The Hellcat uses a
Layton type supercharger. The nice thing about modern muscle[Camaro,Mustang] is that it's now everywhere instead of only at swap meets and now a rarity. I can get parts at a dealer.
Buy a road racer like the Shelby or new Camaro. The 2016 Ford H.O. V8 is gonna have a 180 degree flat crank like a NASCAR V8. The new Camaro SS is starting to turn corners like a Porsche.
Don't stay in the past:
It's like bringing a flintlock to a machine gun war.
Thanks for taking your time to make the video, as a SBC guy tying into my first BBC it helped.
petersdraggon I’m in the same page
I'm looking at a 57 Bel Air with a 454 and a 3 speed tomorrow. Your video has a lot of useful information. I love this, but I have no idea what I'm doing and I'm almost 100% lone wolf in this.
Very helpful, lots of info. Could you possibly do a little closed chamber vs open for the street?
I would avoid the closed chamber heads all together they had big time shrouding issues with the cylinders and chambers, none of them really worked very well as far as factory heads go for the street 049 or 781 is what you want run em with bigger valves and a dome piston and you have an easy 500+ HP
I will be rebuilding my first Chevy big block RV 454. I have own plenty of Chevy small blocks throughout the years. The heads that came on the RV 454 are 045. What can you tell me about these heads? The engine will be used only for street use, no racing. The motor will be going in a 1970 Chevy Nova with a 700r4 transmission with a 2200 stall converter and 373 10 bolt rear end. The only thing I will be installing on the motor is a Comp Cam 274 with springs, locks and retainers, may be bigger valves depending on what it comes with. Any info would be appreciated, thanks.
very nice video with some good info i have a 85 c-30 with a excellent 454 its an old ambulance tons of heavy duty parts and its a dually i want to pull the engine but i have no idea what to do with it just too many options
Great video 🇺🇸👍
my head casting numbers are "336781" in the video u say the "366781" heads are good. was this a typo or do I have different heads?
will schuck They are somewhat average truck heads, pretty good all around performance. If you want better performance- especially higher rpm- you want heads with numbers starting with 38, 39, and 62. There are many specific versions, but the above stated first numbers will be better than the later heads with 33, 34, 35.
hey i think it was a typo cause i have a 1977 454 and i just looked at my heads and there the same number as yours with 2 inch oval ports and i also looked for 366781 and that casting number is not in the gm castings theres a 336781 and thats the only 781 that start in 3 so id say your in the clear
So just curious are the 402 stamped or marked as a 402 or is it still marked as a 396?
1970 LS5-390hp(corvette)&360hp(chevelle)/500ft lbs, LS6-450hp/500ft lbs
Just curious, I have 781 heads on a 489, I had them put 2.19/1.88s in them at the machine shop. Is that the more popular valve size or would more people use the 2.25s? Also, can having too large a valve actually have a negative effect on performance or is it all down to port flow?
my neighbor has a 1972 monte carlo with the 402 . 66.000 original miles.. car is in excellent shape.. he wants 13.900 for it,, its sat in the garage for 12 years.. not sure if its a good deal.
Got a set of 891 on a 477 can you tell me a little about them I believe they are a old pro stock head I know they have rectangular 380 intake runners note these heads are on a race car not street car
What is better open chamber or closed chamber head I have 781 head and 219 for a 496 stroke
The 781 is a much better flowing head the closed chamber BBC heads shroud the valves terribly.
Where are you located? Can a set of the large oval port heads be purchased directly from you?
Do you have an opinion on 359 heads in comparison to the 049 heads
Nice I do like LS engines but BBC will always by fav
Same here. The LS engines run like a bat out of hell, but NOTHING will ever make torque like the old big blocks do. I prefer the old school stuff.
+kctransplant70 you can buy a few bbc from gm not the fun ones tho just 454 502 572 and 427
BBC is way cheaper to get into compared to LS, BBC doesn't care if it runs fuel injected or carbed, LS is built in such a way that expensive aftermarket intake manifolds are necessary in order to just install a carburetor. a lot more BBC stock available too, LS just isn't cheap enough for an intermediate enthusiast to start building. Also for towing purposes and good traction in the snow, the extra weight in a pickup truck from the cast iron BBC is going to help keep the front end tires pressed down, the LS is going to be too light to haul heavy loads, and won't have near the stroke torque these things can output.
Midnight Mechanic the manifold to carb a ls1 is expensive because it has to flow a lot you can get cheap manifold but they don't flow that's why ls1 is so popular because 350 hp 350 tq stock a lot of big blocks make torque but hp lacks 430 tq 190 hp runs out really quick
@@utahcountypicazospage5412 they never made a big block with 190 lowest at there worst was 230 and a cam change headers intake and good ignition puts them up to 400hp.
Good information for us beginners. Thanks for taking the time to explain. Helped me a lot
so you bought a ford or dodge then. ?. 351c will kill any chev..
I appreciate the time taken to make these videos.Cant get enough good info.
Im currently running a 454 gen6 with a 502 cam.
For oval ports the 781 and 049 castings are the best iron oval ports that Chevy came out with. With big valves and a mild port job they actually perform quite well.
if you have a high compression engine low compression with these heads equals no power
@@douglasadams6024 your comment makes no sense. Car Craft did an engine build with TRW flat tops in a
.030 over 454 with 781 heads and a flat tappet hydraulic cam and the combo put out 425hp and over 500 ft/lbs of torque. I have basically the same engine and in my Impala it ripped for a heavy car and 8 to 1 compression. It all depends on what you are trying to achieve.
045s were decent heads as well. Ovals, were not peanut ports
Not really@@douglasadams6024
1970 454 LS5 engines were rated at 365hp and LS6 engines were 450hp. The reason for the 402 in 1970 was emissions. Engines larger than 400ci had less restrictive emission standards and big block chevy's were NOT good with passing emissions. Therefore all 396's became 402's The 396 badges were marketing since the SS396 had become a legend.... and SS402 just didn't have that magic.
I just found a 450for 289 casting it’s rusted should I just leave it
@@Dustinscustoms grab it, if it turns over, how much do they want?
I know the emmissions issue was to do with the closed chambered head, it was horrible on combustion strength, so yeah that open chamber head along with the bigger bore was their solution.
I should have read your comments before I posted mine. Lol
1965 L78 396 425 solid lifter square port 4 bolt mains....own it since 1982 and love it...
The 366 is a truck engine a low rpm stump puller not allot op hp but good torque has poor breathing heads
True, but the 366 is a GREAT source for forged 396/427 crankshafts!! Because of the heavier truck pistons, the counterweighting on them is perfect to use them to build a 396 or 427.
kctransplant70 Agreed we used to buy them from the farmers where I grew up they would just buy a new 366 for their trucks and lay the worn out one out by the barn we could usually pick em up for 50 bucks
Yep! And the crank alone is worth more than 50 bucks!!! They have really good rods and main caps too!
yep that dual thermostat monster former gm tech here
if you think an LS 6.0 liter truck engine is a stump puller, clearly you have never driven and have no clue what a 454 is capable of, or a 396 for that matter
Love those peanut ports! I have had lots of big block street cars and the 236 heads are by far the best heads for torqe and throttle response! My budget 454 just went 11.60s with 236 peanut ports.
Those heads are not peanut ports. Lot of misconception about the bbc heads. There are 3 types. Rectangle-oval- and late model small oval peanut ports. I have those 236 heads also.
@@antilaw9911 236 are not peanut ports? So what are they?
Yep mistsken you are correct
And I agree with you. People are bench talking. Using larger volume heads to gain a few more horsepower at the expense of losing torque and response is going against the grain. With that fast velocity you can still run a long duration cam and keep your vacuum response.
@@antilaw9911 exactly! I had a flat top 454 with 781s and a xe268 cam and it might have been just as fast or faster as my peanut port street motors I’ve had but in a truck or a heavy car with 3.08 gears and a tight converter those big ovals felt a lot slower down low (where 90% of my driving was) I will admit though with the right cam,gears and converter the big ovals will make more power and be faster at the track!
Good video. I was hoping you would've covered the early closed chamber heads. How do they flow vs. the open chamber head? I've heard a lot of different opinions.
My first bbc .30 over 454 had oval port, closed chamber big valve heads it made enormous amounts of torque, also done extensive port matching, it ran very well. Great video!
I had just built a peanut port head build, has a very mild hydraulic cam, 10.5:1 comp with a torker 2 intake, 2 inch spacer and demon 850 carb
That motor in a full interior 78 z28 with a cage and 4.11 gears ran 12.9 at 104 mph, really impressive motor
The mystery motor was the MARK III 427. A "Porcupine style" canted valve design. Quickly protested in NASCAR by competitors it disappeared for three years until a block showed up again as the MARK IV Turbo-Jet 427. 1963's Mark III- Deck height/rod length= Mystery.
After Pontiac ceased producing their own V-8 in, I believe 1979-1980? They had some of their idle head designers churn out a few sets of Big Chief cylinder heads for the Chevrolet Mark IV. These may qualify as factory for restricted class racing. If you find a pair of those, buy them. They will out-do any factory iron 60's style head that the best port/weld skilled shop could turn out and many modern aftermarket alloy CAD designs too. The pinnacle of the factory cam in block- tall deck Mark IV head.
Oldsmobile produced a limited quantity of factory webbed girdle alloy V-8 blocks in the early to mid 80's. Aimed at Drag/ Pro-Street types. Capable of displacements of 700 cubic inches just add the Big Chief Poncho Heads. Factory cam in block Mark IV V-8's became legend on Woodward Avenue-Take No Prisoners. Again, a very rare Chevy BB Variant.
A couple of corrections:
The 496/8.1 was sold new up to 2010 as a motorhome engine for the Workhorse chassis. It should also be noted that the 496 is a LOW RPM motor. Red line is 4800 rpm, and you do not want to exceed that. Its a great low rpm motor, but not good to scream it for HP. The crate 502 is much better for that.
Second thing to point out about heads. Fast burn heads are tons more efficient. The combustion chamber is much tighter around the plug area. The most efficient time to push on the piston is at 14 degrees ATDC. Energy occurring before that time or after that time is less efficient. Fast burn means the pressure build up occurs within a narrower window, so that more energy is closely timed to occur at 14 degrees after TDC. Not only does this improve efficiency, but in addition, the faster burn reduces the likelihood of detonation. As a result, higher compression ratios can be used on pump gas. 9.1 on 87 octane. 11.7 on 93 octane.
Not true. Higher octane fuel gas slowed burn rate.
Let’s do a part two and talk about close chamber and open chamber why the differences and what to look for ? Thank you. Great job sir.
I work at a high school and our emergency generator has a turbocharged 496 running on natural gas.
+tim jones wheres that school ???
u gonna go there in the middle of the night and get ya a motor?
@@jeremyvickery397 🤣🤣🤣🤣🤣
You are exactly right about 427’s and oval port heads. I have a 427 in my 1966 Chevelle and I surprised an LS6 Chevelle and beat him easily. He sold his 1970 stock SS after that which was a shame. He said “I have rectangular port heads so I should have at least 100 more horsepower than you do!” Wrong! That was in 1983. I still have it and it runs great. I saw him at a grocery store a few months ago and reminded him about it but he said he didn’t remember the race!
Been watching your video's, they're great ...wish you built engine in Los Angeles. Keep up the good work.
Hey there i have a set of the 353049 heads, what size was the valves you put in them?
int 2.120/ EX 1.880
Also, BTW, Gen 7 BBC is in current production for marine use. They have not stopped the BBC< just stopped putting it on the road.
Marine production is boats not cars so until gm starts putting them in to production cars the big block is dead.
Big Block opinions are like assholes, everybody has one! BBC's have so many building options. All that matters is the correct combination of parts to get the motor you want.
"Datonya" 😂😂😂😂😂
That was intentional I'm guessing
Yep, that Factory GM "Mystery Motor" was a very rare, exotic "short stroke/big bore/big block" engine, and something like only 20 of them were ever produced by GM, and distributed to Junior Johnson, who got 6 of em, Smokey Yunick got 6 also, and I forget who else may have got a couple, but I know that NASCAR rules required that ANY new engine HAD TO BE made available to the competitors ( only 1 or 2 motors each ) running Ford & Chrysler, so they could "inspect what they were running against". Junior Johnson immediately bought all the other Mystery Motors BACK from the competitors, except for Smokey Yunick, who kept his 6 motors. That way, Junior Johnson had enough of these motors to last the entire season. IT RAN LIKE A BAT OUT OF HELL. Junior Johnson led EVERY race using them, and if the engine didn't fail, they WON the race, just spanking the competition. But the problem was, the heads were plagued with valve train issues. If it lasted, it DID win the race, plus led the most laps during any race that it won.......if not, it LED the race until it quit running. Of course Johnson & Smokey built these engines to produce what Johnson claimed was around 800 hp, in 1963. There's a video here on youtube showing Junior displaying one of the actual race cars with this mystery motor set up for the big tracks ( Daytona, Charlotte, etc....the Talladega track had not been built yet ), in which the car had some serious innovations itself, in addition to the mystery motor. He stated that "Had the motor held together for every race, THEY WOULD'VE WON EVERY RACE THE ENTIRE SEASON, and he was being dead serious. Look for that video.
Nice video. I have been running BBCs since 1970, when I swapped a 1967, 350 HP Chevelle 396 into a 55 Chev Cameo. The reason I brought this up, is that my heads have the D port, which is D shaped large oval port. I can't remember, but I thought it was a 208 casting. This was a weird engine, in that it has the factory high rise Holley manifold and carb. It is a fantastic street engine.
I also have a 68 427 and 2 454 engines. I mention this because, my 435 HP 427 has a heavier piston than the 396 and the 454, which means that it also has a much larger, 8 inch, front balancer. The other thing that you might mention, is that the heads had three, maybe more, different chamber designs, the closed chamber, the partially open chamber, and the full open chamber. I thought this might be important t mention, because the pop up pistons for these different chambers are not a universal fit and caution is advised when mixing and matching heads and pistons. Another thing, I thought was important, was that the 396 and 427 are internally balanced engines, and the 454 is an externally balanced engine.
I know you couldn't mention everything in one video, and I did enjoy it.
I love these
Just saw this video. You left out the little know 366 big block. Also head casting number is 336781 not 366781.
Nice job. Wish you would have talked about the closed chamber and open chamber heads.
Yes me to I have a L36 427 out of a 69 Vet w closed chamber heads
Lloyd Stolworthy closed chambers shroud the intake valves and decrease flow. You can have the chambers plunge cut to “relieve” the intake valves and get the flow rate up to match the open chamber flow rate.... I have had it done to 66/67 702 CC oval port heads.
Do you know where I might find the small heads ? I'm looking for something in my Tow-Truck. Thanks
Don't sleep on those GM 088 rectangular port heads. my 496 on 9.1:1 CR made 565hp and 600tq. excellent street engine
I agree 088 is a good head
Myvintageiron7512 yeah man I was surprised the power it made
@@Myvintageiron7512 listening on your statement on the Rectangular port head not working on the street below 3500 rpm. THAT would suggest they needed an equal length properly sized long tube header to make the work on the street.
@@w41duvernay rectangular port heads work very good on the street. It comes down to the combination of parts. 💯
Now can you port out/port match a peanut port intake to a large oval??
Awesome video. Thank you. I would also like a part 2 on the BBC heads.
Thank you for the very informative vid. I'm not a BBC guy but currently dealing with a boat motor rebuild with a Gen 4 454 and heard about the Rec/Oval ports and didn't know much about it. Now I have a better idea of what's going on. Thanks Again!
IMO the only great improvement in the new engines is fuel injection and coil on plug design. The basic engine have not changed enough to make any real differences. Lets face it folks; a carb engine with a nice came sounds better that an injected engine with the same cam profile - just sayin!
BTW there is no substitution for cubic inches.
If the block hasn't got enough cubes stuff a huffer on top and over drive it.
EXCELLENT EDUCATION AND I LEARNED SO MUCH!!!!! THANKS FOR SHARING!!!
Glad it was helpful!
You are sorta correct on the Mystery engine. It was more like Gen. 1.5 as it did NOT have a gen II bottom end. It was a block that was closer to the 348/409 blocks in design but modified for the gen II heads. So bottom end was truly a mystery as it was not a 348/409 OR a 396!
Ya the 396 was rated up to 425 for the first year in the vette, not just 375
Just recently purchased an old K30 Camper special Dually with a 454 in it. Appreciate you taking the time to get novice mechanics like me up to speed on the older specs and differences. Plan on taking your advice on getting torque out of the engine I have and switching the heads to match up with a 750 carb. Not looking to make rediculous power, just good torque for pulling 7-10 tons on a gooseneck.
I am building a 454 from a winnebago as well from 1978. It has the 781 heads on it. I'd say yours are 781s as well. Should make a beast of a pulling engine for you.
i want to buy a better intake manifold for my 94 bbc.?is are the ports oval or peanut size??? thanks!!
what's the casting number on the heads?
All engines are bored from the factory they just went .030 larger during the boreing process
Best video I've seen on big block gm heads!
Very informative. I’d love to see more on 454’s. I just bout a 1987 GMC 3/4 and it needs attention. Anything you can post will be helpful. Thanks.
Please do a video on talk deck 427/366 BBC
Did you ever get any more information on that motor and heads
I used to build stroker motors out of 427 hi-deck and this was before 502 or 572. Easy to build a 520 and still have thick cylinder walls. 12-71 with alcohol with 300 hp NOS and it would put a smile on anyone face. Unless they were racing you.
I am confused on the 396/402 thing. Your saying GM cast 396 blocks and then bored them .030 before building them to be installed in vehicles? Makes no sense. Are you sure it is not a block cast with a different bore?
It's the exact same block with a .030 larger bore
So they are the same casting, and GM bored them at the factory?
Paulsmarine .Services Yes. Same casting numbers and everything. GM just started boring them .030 over from the factory for the 1970 model year.
!970 EPA rules made a break for engines or 400 CI. Instead of the using the 396 emission standards it was cheaper to bore the motors to 402 and meet the emissions standards with just a carb tuning and PCV.
I have a set of 049 Heads with bigger valves huge port job, 11 to 1 in a 454 .060 over making 632 on the dyno. Running 114 race gas. These heads are so nice. I'm running a Clay Smith solid lifter cam nice power and tons of torque. I really liked your video a lot, very informational, Thanks.
I'm running 9-1 with 049s on 89 making 500
Its just a 468 tho
a fuel injected well built 496 big block will respond the same and make more power ALWAYS than a LS(yes even a 454lsx and tittanium rodded lightweight valve 427)
I believe the 396 was available in 1965 with 12.5 compression ratio rated at 425 h.p. They were called the nascar motor and was available as a crate engine to regular consumers . I Knew two racers that each purchased these motors . They were very potent and sounded very badass . Another friend bought a 66 chevelle , if I'm not mistaken , had that very same motor . I think this was called the Mark IV , or Mystery Motor , and some guys , back in the day , called it "The Nascar Motor".
The 396 was available in 1965 in full size Chevrolets rated at 325 h.p. I know, I had one in an Impala SS. Less than 1,000 were made.
@@stevegladstone7846 in 1965 they made 200 Chevelles with a 396 that they rated at 425 hp. They had a hydraulic camshaft.
Unfortunately, no stock iron Mark IV head is impressive these days. They weren't impressive 30 years ago when I built my 30 over 1/4" stroke tall deck 454 (489CID/8.0L. 688HP). I went with World Merlins.
What about all the good big blocks like the ls6 454? And the crate only Ls7? A lot of left out information.
dirtdobber00 yeah me too. LS7 ESPECIALLY; THAT HOW EXOTIC THE LS7 NOBODY HARDLY KNOWS OF.
Don't forget the ZL-X 427. It was essentially a ZL-1 with an iron block only sold over the counter, not as famous as the LS-7 crate motor, but popular in it's day.
Yes and nobody ever talks about the Tonawanda aluminum block big block Chevy
I’d love to see a part two. Thank you very much for the video. It was really informative. This next summer. I’m going to be rebuilding a 454 for a 4 x 4 truck. Are any of the mid 90s 454 heads better than others? Thank you. God bless you and your family. Duane.
part 2! seat hardening etc
I'm looking at getting a 76 one ton 4x4.. has a 454 I would like to make a 450 to 500 hp off road truck... how can I start this.
build it with 10 to 1 compression some good after market heads or ported 781's and you have an easy 450+ hp engine
Casey Myers first of all check and see what you got for heads. Most likely there going to be a peanut port and you dont want to startout there. But there are many iron oval port heads that will easily make 1hp per cubic inch and you can usually find these heads out there somewhere for sale. Ideally you want an 049 or 781 but 279s and 156s can be worked a little to breath fire as well but porting and valves arent cheap either
Start putting together 5 grand. five hundred dependable horses out of a BBC is easy. stay away from high compression, square port heads unless it is strictly a all out WFO racer..
Thanks for making this video. I have a 454 engine in a Cabin Cruiser style boat that runs in the lower RPM ranges below 4200 and I was thinking of changing from the peanut port heads to the square or oval port. After what you've explained the heads I have seem to be the best to use for the most torque which is what's needed in my type of boat. Very good video, Thanks !
wiboater4 peanut port heads work well in a boat Id leave em alone
That's good news. I'm in the middle of building a 454 w/ peanut ports for my 27'Sea Ray.
oval port and a 168731 crane roller cam.... easy 500 hp 550 tq
1st off: thank you for responding to a camshaft question I had for you couple years ago. 2nd, I later watched your video about choosing camshafts and it really opened my eyes to the whole cam theory. 3rd and lastly, need your advice yet again on another situation. Just acquired a '68 L78 396 4 bolt main for my 68 Nova. The guy through in a set of 390 (427 heads) and I bought a set of 990 rectangle port heads from him (which were actually on the engine, put on the engine at some time beings that they appear to be '73 year heads). So far from what I've gathered is that the large oval port 427 (390) heads are proven better for daily street type car situations (which is what I intend to use the car for). I don't intend on seriously racing this thing. Just want to give it some more power (the 'ol 267 4.4 is dependable as hell, just ain't cuttin' the mustard in the way of "performance driving pleasure"). Hell, you actually spoke of this in this video as well (power being made at low RPM's). And yeah, I've read it elsewhere too like I mentioned, but I've gotta ask you straight up exclusively because your really the only reputable guy I know (can think of) who really knows his stuff. So, I have to ask. For a every other day driver 68 (4dr at that) Nova, what would you recommend I put on this 396? The 390 oval port heads (which I'm assuming are "large oval port")? Or the 990 "hi perf" rectangle port heads? Very much looking forward to your input on this so that I know how to properly move forward with this project. Thank you for all of the knowledgeable videos you post. They make sense, are easy to understand and really help out folks like myself who lack the knowledge.
The reason behind the 402 was a fire in the warehouse that housed all the 396 blocks and they had to punch them to a 402...
Warehouse fire? ARE YOU SERIOUS? Or seriously a troll?
Old school Chevrolet Jargin turbo fire equals small block turbo jet equals big block
great channel!!
gen 1 is w motor
John Lingenfelter found that oval ports out-performed rectangular ports by a good margin up to 800+ horse power. On a 454 with about 475 hp with rectangular ports the switch to oval ports added almost 100 hp. On a 496 with 560 hp using rectangular ports he picked up 70 hp switching to oval ports. The oval ports were 049 or 781's with larger valves, a port match and smoothing the short side radius on the intake port. I know most older Chevy guys know this so this is for the younger guys. Don't waste your time on rectangular ports unless you're building a 572 prostock motor turning 8000 rpm's in a 2500lb car. They just aren't good for the average high performance application.
I love it when you guys post good solid information, you are so right the 781/049 heads are killer street/strip heads and they make make mad power I have a few vids where I install the big stainless valves in those heads The most important thing to remember is they are open chamber heads and they have around 120 cc chambers this makes pretty low compression on a 454 you need a .120 dome piston for pump gas for around 10 to 1 more dome for race gas I love these heads I am putting them on my 502 with a .060 dome forged piston
Thank you. I bought a 1970 Corvette in 1995. It had a 454 that wasn't numbers matching and the seller didn't know anything about it except it was supposed to be a 454. Someone had ground the stamped numbers off the front of the block and tried to restamp it as a 1971 LS6? I took it to the dragstrip and it ran good consistent 13.40's-13.50's all summer long. That winter I pulled the intake(a factory GM aluminum) to find rectangular port heads. I then looked up the block and head casting numbers and the date codes and it turned out to be a complete 1970 LS6. I built a set of 049 heads like I read Lingenfelter doing and put them on it with a performer intake and a Crane grid hydraulic cam. My Chevy friends almost cried when they saw what I was doing. "You took the better heads off for a set of smogger oval ports" they would tell me. The next spring at the drag strip I ran a best of 12.21 with consistent 12.30's. Some of my friends shut up and took notice, others still to this day stick to the assumption that I made a mistake. I sold the 291heads in the local paper and a guy restoring an LS6 Chevelle bought them along with the aluminum GM intake. The money I got for that paid for the other parts plus a little cash in my pocket.
Very good head swap, rec port heads are great if your running 7000+ rpm's
1967davethewave depends on the engine combo. Rectangular port heads can make good power as well.
You're right Dave the wave. Remember the little over 700 horsepower solid roller big block Chevy blower motor oval irons vs. Square irons. The oval irons won horsepower and torque the square Port irons lost. The average square Port and 990 head had a 325cc runner it didn't flow to good and was too big. And remember when guys took cylinder heads ported and Polished stock heads and hurt the horsepower and torque they Dynod the motor after putting it back together wasted a lot of time and money and then to have less horse power and torque. I guess we've all seen people go to big carburetor intake cylinder heads cam headers and hurt horsepower and torque.
Excellent video! I have a 1969 BB 427 out of a Corvette that is my project engine for my 56 Chevy. Good information!
He's wrong about the 396 horsepower ratings. The 396 was introduced in the 1965 Corvette and rated at 425 HP, not 375. The 396 Chevelle came later that year. It was rated at 375 HP. It was the same engine as the Corvette but with a different horsepower rating. Very few 1965 396 Chevelles were built. In 1966 the 396SS Chevelle came into its own still rated at 375 HP.
Donald Smith That's right. The L78 396 (awesome engine!) was rated 425hp in the vette, 375hp in the chevelle and camaro. This might be more legitimate than it seems because of the difference in exhaust manifolds. The corvette had much better flowing exhaust than the others. But, throw a set of headers on any of them and you have a screamer of a big block.
I still have my 1965 396 Corvette. 36,359 miles.
+Donald Smith The 396 also came in 1965 super sport impalas, my 65 had a 325 HP 396 with 400 TH transmission.
+Barry Kremling , very true, we have a 1965 impala old police car that also had the 396 325hp with the th400
Are you sure about that it was 425 instead of 375 on a 396 I'm a Mopar guy and I'm going to question that I'm building a 67 GTX by the way but just going through the comments Donald that kind of threw me for a little bit of a loophole I get back to me like to pick your brain fellow Gearhead Mopar or no car 67 GTX ragtop for Speed 440 balanced and blueprinted 4:56 gears with a 4-speed
I realize this info is not new I'm just putting it out there most now days don't read they Google it when they want to know something most of what I learned about of engines is from experience quite honesty I have never read those author's you listed either
I'm up in the air between a cadillac 472, buick 455 or building a 454. I'm on a budget and it's going in a Buick 65skylark. I can get all these engines for under 400$. I don't really understand the difference between a screamer and a torque monster and the reason behind why one runs out of power faster. I want something strong, snappy and able to drag race sometimes.. Thanks a lot I always watch your videos and I've seen the 455 ones aswell
Ronald Almendarez Get a 455. Super torquey motors, and if it's going in a Buick might as well.
IF YOU ONLY HAVE 400 BUCKS FOR A MILL STAY AWAY FROM THE DRAGSTRIP. You will be embarrassed by some 16 year old kid in a Honda civic who has 2 grand in the headwork. BTW THE CADDY IS A TURD except for making a lot of torque. I will give you a grand for the Buick frame if it's a good one.
I put a 455 on my 84 K20, best motor ever for a truck. I never got around to it, but Mondo is a BOP motor specialist place, they make a stroker kit that makes it a 496. Numbers advertised are silly, if I remember right 510lbs torque @ 2800rpm. Awesome stuff lol
Ronnie Buicks u need to go watch the episode of power Block where they show the Defense between all the GM V8 and y the chevrolet V8 small and big block came out on top.
Build that 455 put money into the heads and you can have a lot of fun and have a very respectable street car
Two decades ago, I had a 454 from a late '70s pickup for my Malibu. I had an Offenhauser rectangular port intake for it.
So I port match the heads to the intake not to far to break into the valve spring area, just to give a smooth transition between the intake and heads.
I have no clue if ever I had performance gain with this, but the damn car ran great from stop lights to the highway, no issue in throttle response or surging at high rpm (4800 lol)
So I wonder if I can do the same thing with my stock tbi 1991 peanut port engine in my K3500, if I ever decide to install a better cam, chip it and put the tbi unit on a performer oval port intake. Just to improve the performance a bit, without altering it's great hauling duties!
Thanks for this very informative video! I'm a subsciber now!!
How reliable are the 88-94 454 tbi engines?
Thanks! Found a 454 in a 92 truck. $200 later its mine and we're working our way, economically, to. over 500 horses. Love the BBC's!
Hows it going?
Dude great video I was impressed on the new teachings. For me going to school to be a mechanic I still have a great deal to learn even though my dad is a master ase mechanic. Hey man thanks for taking the time to produce this sort video. Well keep your engines rockin and the tacs a knockin.
A couple more details about big block history: In mid-1965, the first year for the 396, it wasn't just the Corvette and Chevelle that was offered with a 396. The most common 396 was the 325 hp 396 (L35) that was available in the Impala/full size cars. I have one from a 65 Impala SS. It wasn't mentioned, but in 1970, the Chevelle was available with the famous LS6 454, 450hp engine. And a correction: The 1970 LS5 engine wasn't 440 hp. The 70 LS5 was produced in 2 versions, a 360hp(Monte Carlo SS454 and Chevelle SS454) and 390 hp for Corvette and full size Chevrolet. But the 360 and 390 hp engines were basically the same, with ratings measured at different rpm levels. So the output difference was just on paper, so they basically had the same output in reality.
The 496 stroker is a little different than the 8.1L vortec. Its 4.310 bore .060 over 454 and a 4.25 stroke. Just sayin :)
All true
Vortec L29 heads?
Thank you so very much for all your history on big blocks and all you info on heads! Very helpful!
Definitely want to see more on the big block chevrolet! Make a part 2 please!!!
I'm trying to decide witch oval port i had on my 73 c10 454 pickup truck. I had my heads of due to compression failure in a sylinder. Turned out it was a hydraulic lifter that had locked itself at max, so the valve stayed open all the time. Wish i had checked the lifters before i took my heads off :)
This is alot of years ago so its hard to say what i had. But i remember i thought back then that the intake ports looked huge.
Didn't some of the Cadillac cars have a 502??
500 ci and not a chevy engine a caddy engine
The LS5 was factory rated at 360 or 390 HP (depending on the source) and 500 lb/ft of torque, NOT 440 hp and 590 lb/ft. They may have actually put out around 440 hp, but 590 lb/feet is WAY optimistic. The LS6 put out 450 rated horsepower (probably closer to 500 actual horsepower) and the same 500 lb/ft of torque as the LS5.
9.55. are you sure that the 502 has a different borespacing than other production bigblocks? 4.840"
It's not
When you talk big block Chevy your knowledge suffers no LS 5 454 was rated at 440 hp they were factory rated at 390
The 502 had the same bore spacing as every other big block at 4.84 inches. GM has never changed the bore spacing, only the aftermarket has. The 1970 LS 5 had 360 hp in the Chevelle and 360 hp in the Corvette, not 440 hp. The LS 6 had 450 and only came in the Chevelle. As far as the rectangular port heads are concerned, they are exactly what you need in a 454 or bigger engine that is expected to turn 6500 and will reward you with sparkling top end power. The oval ports work fine but do not flow enough to feed an engine that is big and/or will have the cam to generate higher rpm and the expected high power up there. Remember that the big blocks, especially the 454 have a short connecting rod and a low rod ratio. This means that the engine can activate a large intake runner and needs enough volume to feed itself. Having the shorter rod generates better low end torque so the effect of too big an intake port is masked. Compare this to a 440 Mopar with it's really tall deck and really long rod. The intake runners are tiny compared to the Chevy square port runner. You can put one runner of a Chevy rect, port intake gasket over both intake ports on the Mopar intake ports. Don't be afraid of the rectangular port heads, the factory created them for a reason and they are the bomb on the right application.
402 also came factory in the Monte Carlo. Also I’m pretty partial to the Gen 6 heads for a street car. They flow pretty good and make good torque on the low end
So if I want build a torque motor I use peanut head if I heard right hope someone answer my question
yes the smaller the port hole the better torque you will have
As I recall, the 1966 Chevelle 396 came in a 325, 350, and 375 hp.
360 not 350
LOL yeah I suppose your right Ford should be done as well
We found a 1969 Chevy impala custom with a 396. What year is this 1965 or 1970 big block?
You should do a video on the best casting #s of the 454 motor. I have been looking to build a 454 and I am confused about which casting is the one to get for the best performance with the 781 heads. Thanks for all of your hard work and awesome info!
There are a few videos floating around about bolting on a set of heads out of the box. Generally, is there a process you go through with a brand new set of castings (assembled/bare)?
Yea buy em bare and have a good shop do the valve job never put an assembled set on out of the box the valve job is usually pretty bad
I love that you touched on the 402 BBC. In my 1947 Ford truck sits a 1972 402 big block Mark IV LS3. Not going to win many races but it was my father's daily driver. This motor, transmission and carburetor all came right out of the same vehicle together and that's how they will stay. Good stuff :)
Only one discrepancy in this video. You said that the Ls5 was 440hp. Actually you were describing the Ls6,and the rating was 450hp on that particular motor (conservatively). But I have have an awesome set of square port heads that I took off a 461ci because of the low RPM air velocity and people thought I was crazy for saying that I didn't need them on my street driven Chevelle. Enjoyed the video.
great video. as far as what came out and when, people can do there own home work. I understand it's based off your readings and such, either way good job giving us an idea about the bbc heads and a bit of history.
In 1965, the 396 in a Corvette was 425 HP. You could also order a "drag pack" option in a plain jane Biscayne which included a 425 HP 396 and a 4 speed.