Mike what makes you think those are BBF heads ? If the bolt holes haven’t been relocated, they should bolt to your Cleveland block. The E3ZM-C3 is an alloy Cleveland head that was sold by Ford Motorsports “Special Vehicle Operations” , or Ford SVO during the mid eighties. Different versions were indicated by C3, A3, and were used in Drag Racing and NASCAR. They are still very popular today. It looks like each one of your heads was extensively modified but for two different engine builds. The exhaust ports look modified on one head but stock on the other. The raised intake ports is a common modification done to increase flow with a straighter shot to the valve. The thin surface on the intake side might have been done so the head could be used on a block with a shorter deck height than the 9.2” Cleveland or 9.5” Windsor. Spacer plates are available to correct it. The screens that are epoxied into the oil return holes was done to prevent metal debris from entering the block when the needle bearings used in roller rockers would disintegrate at high rpm’s. When grinding the intake port roofs to raise them, the top of the ports near the rocker stands becomes paper thin and too weak to support the stands under high spring load pressure. The epoxy and welding you see in that area helps restore strength and stability. It’s a technique that’s still used today when radical porting is needed. I’m not sure what the 377 and 408 numbers mean. The numbers on the end of each head were probably done by the builder to indicate a specific engine configuration. The Ford SVO part numbers are the same but each head was modified for different engines. That’s my best guess 🤷♂️
They are for a 351 Cleveland for sure, that's really to only reason I bought them and mock up. Im not really sure what the heck I'm going to do with them but I only paid $100. Thanks for all the info again I've done a lot of research and have got lots of good information off here in the comments too. Thanks for watching and have a great weekend.
Mike what makes you think those are BBF heads ? If the bolt holes haven’t been relocated, they should bolt to your Cleveland block. The E3ZM-C3 is an alloy Cleveland head that was sold by Ford Motorsports “Special Vehicle Operations” , or Ford SVO during the mid eighties. Different versions were indicated by C3, A3, and were used in Drag Racing and NASCAR. They are still very popular today.
It looks like each one of your heads was extensively modified but for two different engine builds. The exhaust ports look modified on one head but stock on the other. The raised intake ports is a common modification done to increase flow with a straighter shot to the valve. The thin surface on the intake side might have been done so the head could be used on a block with a shorter deck height than the 9.2” Cleveland or 9.5” Windsor. Spacer plates are available to correct it.
The screens that are epoxied into the oil return holes was done to prevent metal debris from entering the block when the needle bearings used in roller rockers would disintegrate at high rpm’s.
When grinding the intake port roofs to raise them, the top of the ports near the rocker stands becomes paper thin and too weak to support the stands under high spring load pressure. The epoxy and welding you see in that area helps restore strength and stability. It’s a technique that’s still used today when radical porting is needed.
I’m not sure what the 377 and 408 numbers mean. The numbers on the end of each head were probably done by the builder to indicate a specific engine configuration. The Ford SVO part numbers are the same but each head was modified for different engines.
That’s my best guess 🤷♂️
They are for a 351 Cleveland for sure, that's really to only reason I bought them and mock up. Im not really sure what the heck I'm going to do with them but I only paid $100. Thanks for all the info again I've done a lot of research and have got lots of good information off here in the comments too. Thanks for watching and have a great weekend.