340 piston in 360 block : take off bout 0.10" from piston crown if it's thick enough, add a 0.080"head shim on the engine side with a standard 0.038" thick head gasket gets you 0.118" to work with. Subtract from the 0.27" sticking out....you need to shoot for the perfect 0.030 squish/ quench
@tdc for the turbulence it creates in your combustion chambers...measure carefully and take in to account your rpm, stroke, stretch at the high end...
