all i know is my car is going to performance factory over the winter my appointment is already scheduled, i am just waiting to get laid off for winter, it is gonna be getting a vortech charger kit i have decided on and safely going to be 400whp stock internals, for my daily driver, this is only on 8 psi., then down the road maybe bump it up a little but should be good enough for a daily driver, then i can get going on project supra. lol. and right now my car would walk a older z28 like you say you have, no questions asked.