Not sure which 2008 GMC Sierra Exhaust Headers & Manifolds are right for you? We have over 918 customer reviews, with an average rating of 4.5, to help you find exactly what you're looking for. Here's what some of our customers have said:
"Use the factory gaskets and go to NAPA and get a steel flange gasket. The paper gaskets will blow. Other than that, love them. Super easy to install." —Daniel A from Helotes, TX bought a PaceSetter Shorty Headers for a 2008 GMC Sierra.
"I strongly suggest the purchase of a 1/2" 15mm deep, 6-point and swivel adapter for your extention prior to trying to remove the factory exhaust. It took just 3 hours (could have been two or less with a 6-point). My only complaint about the new is the stuggle to secure the passenger side collector around the cat.
Not much change in tone, better responce for passing-mid to high rpm. 8000 miles so far no leaks, no loose bolts, very impressed with direct fit" —Garret B from Nottingham, MD bought a JBA Cat4ward Headers for a 2008 GMC Sierra.
"On my 2008 GMC Sierra Denali, these fit perfectly. The improvement in power was immediately noticeable. Better throttle response with faster revving with much more rapid acceleration. I had several other mods already on the truck (CAI, cat-back exhaust, programmer), but this one piece really pulled it all together. I'm not sure if the improvement would have been quite as dramatic without those others in place, but whatever the reason, this single component made a marked improvement.
Aesthetically, these are very good looking ceramic-coated headers. They take up considerably less room than the stock headers, especially since they don't need the heat shields. They permit more of the internal engine sounds to escape as well, which adds a nice mechanical aspect to compliment the V8 rumble out the back.
Installation will vary depending on the truck, and will probably require a lift." —Brian M from Springdale, AR bought a Doug Thorley Headers for a 2008 GMC Sierra, 1500, 6.0L V8.