rondun
Active VIP Member
I had to take out my cats due to being pluged the truck runs better, But the stock muffler makes a horrible sound around 2500rpm like the muffler has a broken baffle inside, Anybody know of a good muffler that is not too noisy and flows well 05 GMC 5.3l aluminum block w/6.0l heads and 9.9to1 comp on propane and 4:10 gears truck pulls well (eats a Hemi in a pick up) and gets 19mpg the exhaust was quiet until the cats came out NOT NOW