Mufflers for 2005 workhorse with GMC 8.1

Hank MI wrote:
It's typically a combination of the sound level you're trying to achieve and the engine. Too little back pressure, not really a concern, maybe if you're running open headers. With a full exhaust system, stock exhaust manifolds, catalytic converter, mufflers, it's nothing to worry about.

So it comes down to what fits and what sound are you willing to put up with. Any stock type muffler that fits should be good. If you're willing to put up with a little more noise there are other options. You probably won't even hear the difference from the driver's seat and they can improve performance, marginally.

Thanks Hank. If I have to replace the mufflers anyway, what muffler options do I have? I sure wouldn't mind a little improved performance