Register a free account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members through your own private inbox!
As far as I know the main benefit is more torque lower down. Cutting the exhaust/cat back is expensive and I personally don't think the cost is worth the gains!
Me and Kully have very similar mods, he has the 182 exhaust manifold and made about 3bhp more.