Would it sound ok of I removed the stock muffler and replaced it with a flowmaster super 40 series?

What size is the stock exhaust piping, 2.5"?

 

yes it woul be ok, but most people here would go with a different muffler....

stock piping is 2.75 if Im not mistaken...

 

i believe you are right about the 2.75" stock piping. So what do we do about the fact that most cat back kits / mufflers are only offered at 2.5" or 3" ?

 

If you're just getting a muffler, get a 3", and any competent exhaust shop will make up the difference. If you are getting a cat back, you will ditch all of the 2.75" tailpipe tubing anyway and bolt it up at the Y-pipe flange.

 

 

go with a 3" exhaust w/ no cats custom y pipe and a BORLA muffler from your local muffler shop you trust

 

the stock muffler is single inlet single outlet both centered pipes right?
and its 2.75"?

 

Center/Offset. Definitely crawl under there and check before you order anything. I have a Magnaflow 14589 sitting on my workbench that is getting welded in next week.

LINK

 

I just had two 11259 put on my dads 02 6.0 2500hd in place of the stock muffler and it is pretty loud at WOT. cruising at about 30-55 has alot of interior resonance. Will be adding another type muffler or putting factory muffler back on. I want it quiter. It does idle smoother though.

 

Consider your muffler carefully if you're running a 6.0 or 8.1L. The resonance can be downright brutal. I've flirted with Flowmaster and Magnaflow over the years and finally did I what I should've done in the first place....Corsa Touring.

Sound is subjective, but to my ears it doesn't get any better. Nearly silent at cruise with zero resonance. Nice throaty purr at idle, and your right foot is the volume **** for everything else from a sexy rumble to a ferocious roar.