Hi im new here i have a 86 iroc-z 305 tpi and i wanna put a cat-back system and i was wondering what would sound better the american thunder or the 40 series? also if i put a high flo cat does that make it louder ? thanx

 

Go with the American Thunder system and a Random Technology cat. The American Thunder system has a deeper, more aggressive tone, and the Random Tech. cat will definitely liven up your 305 a bit. Look into some headers also, being that its the most restricting part of your entire exhaust system.