hello,i am new here ,and i have a 2004 chevy express 3500 it has dual cats then goes into 1 muffler and out to one tailpipe ,i want to put dual on,i stoped by a shop and they suggested one dual in dual out of thereown ss muffler,should i do this or use 2 separate mufflers (flowmasters maybe) which will sound better,they say not much of a differance is this true??? thanks alot ps it is a work truck and my car ,so im not to concerned about performance,just sound

 

Go with the better muffler like they said......But there's not a lot of room to run a second pipe over the axle.....You might get a better muffler to fit stock configuration ,but with better flow sound etc.

 

If it's already set with duals into one, get rid of those cats, put in a cross over to help scavenge and equal the pressure. That will also lower your temp a little. run 3" all the way if you have room. If not 2.25 to 2.5 will fit. Put the mufflers as far back as you can, this will give SLIGHTLY more H.P. and improved sound. Got a 95 2500 that has 3" single to dual out 2.5 to 3" tips. Went with flowmaster, nice idle sound not loud, sounds great under acceleration. Waiting for the rebuild to go true duals.