Any Chevy engine, if it's well-modified or just slightly warmed-over, requires a good set of valve seals. Originally, a small rubber O-ring, fitted in the second valve stem groove, served as the only ...
An engine is like a safe deposit box with two locks. You can unlock one of these with such keys as carburetors, manifolds and ignition. But you can't open it up and get all the performance you want ...