Go with what Speed pro recommends for thoe pistons in your application Speed Pro has spent millions of dollars over the years doing research and development on those pistons I think that all of the OEM gas engines made in the USA have hypereutuctic in them now from the factory exept maybe the hi output turbo and supercharged motors, maybe even them


Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)