I beg to differ on the Prochamber - Ive never seen someone complain about it before. They honestly and truley outperform any h or x I've ever seen. Ive got their longtube headers as well on my 4.6 and have had zero probs, other than the coating looking like crap right above the collector. Fit was good, so was the welds.

Of course I know they aren't usually the quality of alot of the other more expensive brands - but Im happy for what I paid for it. And like nomo said you don't want chambered mufflers. Don't get me wrong, the Mac's are loud as hell and deep, but they don't perform well for mufflers

 

OK..thanks for the info. So then is Mac isnt a good exhaust, does anyone have any suggestions? I dont mean to sound like someone who has no idea what their talking about and sound way over my head but for the money im putting up i dont wanna have things like TB, mass air and exhaust lowering my #'s. I want it to be pretty much as good flowing as i can get it. thanks guys for all the help..

 

MAC S F/ING SUCK MAN ..THEY F/ED UP MY COBRA MOTOR MAKING IT SMOKE LIKE A HONDA WITH 30,000 MILES ONIT,,,,ANYTHING BUT MACS I WANT TO THROW MINE THROUGH THEIR WINDOW...

 

I guess i should scratch the mac exhaust off my list. But Im trying to steer away from 2 1/2inch exhaust and getting atleast 3 inch. With all the air coming in, im gunna need to get it out as quick as possible. What other GOOD exhaust companies make 3 inch exhaust. I think im going to opt for the Hooker headers, but what about mid pipe and cat back?

 

I've had mac longtubes for like 2 years. No problems.
What other headers will fit on Gt-40's

 

THE 99 COBRA ONES HAD DEFECTS ,,SLAG GOING UP THE EGR PIPE,,GETTING INTO ENGINE..I WILL NEVER BUT ANOTHER MAC PRODUCT ,,,