So, I talked to the guy I got the engine from and he said he thinks it was running a 650 but not sure, and he was using either 89 or 92 octain fuel. He was unaware of the internals, but that probably explains the piston.

So my question is, what zize carb yould be good for this motor and what fuel would I have to run. Could I get away with a thicker head gasket and just running 93-94 plus octain booster, or am I gonna need a blend of regular and race fuel, if so what kind of ratio?

Butch