I have a 2002 Z28 SS and I'm thinking of adding a 80MM throttle body. Two questions;

Will it help acceleration?

Will it affect the emissions test?

I already have a cold air induction kit and headers installed.

 

Won't do much of anything for you if you don't have at least heads and cam ... and not a whole lot then, since the opening to the intake is still going to be 75mm ... really not worth the money you pay for one on a stock/bolt on motor ...

Just port or get a ported stock TB ...