Agreed.

I'm not saying you wouldn't want to do everything and ideally at the same time. I'm just saying that while a header may not breath as well as it would with a higher flowing cat and exhaust to compensate for the additional flow, you can get away with doing it first. It can be the place to start.

I mean if you only had enough money to do one thing first for performance, other than suspension, what you would do first, knowing that you would eventually get it all done? I personally, would probably go ahead and do the header or the cat/axle back, either one.

Ultimately, it's the whole system that makes the difference. Evacuating those gases and exhuast are what's important. But then you can get into the whole thing as to whether or not or how much back pressure you need and blah blah blah...