Going to be putting in the new motor 350 - 400 HP pretty soon and was wondering if my 3" hooker catback was going to be good enough or is it going to be hurting me. I am going with Hooker LT's 1 3/4 primary's. I have looked at mufflex (way to expensive) or maybe running duals and dumping before axle but if what I already got on the car is good enough to not hurt performance then I aint going to mess with it. Is there a rule of thumb when it comes to pipe size verses exhaust flow??