Camaro- ’89-’92 body engine questions

Based on the '88 to '92 Camaro body style (which i think was around longer than that) What year(s) had the fastest stock motor? I know it has a 5.7 Liter V8, and I'm assuming it would be a Z28 engine, but was one year of the car equipped with a better motor? I'd like to hear all the info that you have. Thanks!