You gotta see this ......

Yes to the above fro 72blunblu. I was gonna ask if the piston to valve clearances had been checked but you beat me to it. Pulling the heads and inspecting piston tops and valves would be wise and good insurance at this point.

BTW, the 2 Edelbrock head models for the SBM have the same rocker and valve geometry. So the piston to valve clearance would not change between the 2 , or anything in the valvetrain action. It would only change the piston to head clearance.