Quote Originally Posted by johntremell View Post
if you get the 2.5" aluminized catback like i did from zzp and you do the ported exhaust manifolds like i did from zzp you probably wont gain any gas milage. if anything you will lose gas milage. however the tradeoff for power was worth it for me. I went with the magnaflow mufflers and resonators and it quite a bit louder than stock.
How do you like your sound with that setup? Is there any header cat back setup that creates HP gain and MPG gain? I always thought for some reason that it naturally would?