The cougar has a little more growl now...
I finally installed my ceramic coated Mac longtube headers and Pro-Chamber...needless to say, it sounds great BUT a major pain in the dick to install...who would have throught that a Mac pro-chamber designed specifically for their long-tube headers wouldn't fit right...on the driver side it seems like they made the s-bend on the pro-chamber too far back so it just stays against the floor and makes every nut and bolt in the car rattle.
Maybe somebody else has had better experience, but as far as I'm concerned, I will never buy another Mac exhaust product so long as I live.
-Don