A borescope into the valve cover won't tell you as much about the condition as removing plugs and going into the cylinder to get a look at the cylinder walls and piston tops. The Valvoline will probably clean up the varnish you see in the valve cover, but cleaning up the rings is how it is marketed and where it will make a difference in performance and oil consumption. The engine sounded ok in the other video.
A borescope into the valve cover won't tell you as much about the condition as removing plugs and going into the cylinder to get a look at the cylinder walls and piston tops. The Valvoline will probably clean up the varnish you see in the valve cover, but cleaning up the rings is how it is marketed and where it will make a difference in performance and oil consumption. The engine sounded ok in the other video.
Thx yea i dont expect much going this route. Still nervous about messing around with the spark plugs just for this