I've got a NBS with the 5.3L in and I cut the muffler off. I didnt lose that much power. It is loud, but I have heard louder. I dont know how it would sound on a 4.8L you can always cut it out and add an aftermarket one in later, or put the one you have in it now back on if you dont like it.
Running straight pipes is not a good idea on the computer controlled vehicles. Not only will you be losing back pressure (thus losing power), you'll be throwing codes left and right. And the factory tune will be off greatly. On a carb'd motor, it was not so bad, but with computers and controls, it is not a great idea.
You'll be better off with just replacing the stock muffler with a Flowmaster, Magnaflow, Borla or other brand. Though, you'll be even more better off with a cat-back exhaust system.
Thanks for your input every one! I am not looking for performance as much as just a nice rumble but I certainly don't want to lose any performance either so with that said i think i will just wait and by a catback. Thanks again!
What I ended up doing on mine truck was putting a magna flow on and then my exhaust guy welded a 4"tip right on the other end of muffler and it has a good rumble. The one thing I dont like is it gets raspy sounding when you put you foot in it. My buddy has the 4.8L in his truck and we have the same muffler the one thing he did different was he dumped his over the rear axle and it has a great tone to it.
A forum community dedicated to all General Motors truck owners and enthusiasts. Come join the discussion about performance, lift kits, wheels, tires, modifications, troubleshooting, maintenance, and more!