You guys are missing the point, you need the exhaust to flow well. its all well and good having this exhaust that sounds amazing but if it flows sh*t then theres a few hundred bucks down the drain when your car wont make over 300rwkw. best idea is to go off FACT, have a look through the 300rwkw owners club and see what power they are making with what mods. Or if in doubt speak to your tuner and see what exhaust he recommends. Chances are they will have worked with alot and can give you a good indication of what will suit you. For example when I go to pitlane ill be like hey mick I want this and he will give me like 4-5 different options on brand etc tell me pros and cons of each and I make my own mind up. also ls1s only have 1 cam. You will never EVER get even close to the note of an 8 with a 6 cylinder car. Its never going to sound "amazing" but who cares? nothing like the sound of 15psi through a 3" intake