Installed on 2003 GMC 2500HD 6.0
Reviewed By Jonathan V (Saint Paul, MN) Reviewed for a
GMC C/K 2500
—3/2/2011 6:43 AM
I installed this muffler on my truck. The only other engine mods I have on is a Spectre CAI.
I highly advise getting it welded, as the clamps just couldn't secure the muffler properly. The shop charged me $150 to weld it- a ripoff, but it's worth it.
Flowmaster says that the GM 6.0 is the hardest motor to quiet down, so I advise getting this muffler. According to Flowmaster, this is the biggest, quietest muffler they produce. The sound is great. Very powerful, not too loud, either. There is a noticeable drone at around 2000 rpm, but I got used to it fast. It sounds great on the inside, and even better on the outside. I did certainly feel a power boost all across the rpm band, but no improvement in mpg's. And as usual, AutoAnything was terrific.