the first motor swap i performed on my z, i put a 12:1 cr, mechanical roller cam, aluminum headed chevy 383 sb, backed by a ford 9" rear end and a t-56 6 spd tranny and a 6 pt roll cage. i say v-8 is the way to go if you have the money, tools , and time to reinforce your chassis and drive train. this car made 460 hp to the wheels and pulled the front end almost a foot off the ground on hard launches. to all you guys who are afraid of twisting up your car- half your car, and drop a chevy small block in your Z