Any longer case straight thru style muffler like Magnaflow or Borla will work well. I would look for around 22-24 inches.

 

This is probably going to be your best option. Silverado53 just mentioned it also, so I figured I'd chime in and say that I'd go with something along these lines.

 

done several of these,best quiet power,chambered so has a slight flowmaster tin sound,no drone 1700rpm LS Drone is a downer for me

not sure If i used the 8880,it was a couple of different ones all good

Big oval baby http://www.flopro.com/bigoval.html

 

Magnaflow 3.5 22 long case on my 6.0 with dual 3s, no cats, y into 3.5 muffler and no tailpipe.....perfect, not loud, no drone, quiet at highway speeds, some roar at wide open throttle......perfect.......

 

The super turbo is making the exhaust very tolerable. I went with it because it's the only muffler close to the size magnaflow that was on there. Has a deep smooth sound with no rasp.
Can you guys post part numbers of the 22" case magnaflow?

 

Are you running a tailpipe or is it dumped?

 

Tailpipe, it's the 3" magnaflow exhaust. Being a RCSB, it doesn't have much room to add a big muffler. I'll try to take a video of it this evening and post it here.

 

Quick video. I like the sound.

http://www.youtube.com/watch?v=agdQ5...e_gdata_player

 

How about we trade y pipes
I have a high flow on road pipe made by GM
It has 2 cats and came on my truck from the factory
Its real nice
I run the factory y pipe and no muffler with no turn down under the bed and it's far from bad. The different firing order really tamed the sound on these motors.

 

https://www.performancetrucks.net/fo...fflers-496693/