doordoc35

hi,i have a 2004 chevy express that has real dual exhaust up to the 2 cats then from there on it goes to single stock muffler.My question is instead of paying a shop to add a di/do flowmaster or similar then custom dual out,can i just cut out the stock muffler out,then add a (si/do) flowmaster then duel pipes from there with clamps and hangers myself and maybe have it welded later? and would it sound good or should i not even think of doing that? 6.0 motor ,thanks

canucklehead

i am in the process of figuring this out for my 02. On mine its a dual in single out muffler.
If you go with factory replacement, you will likely have to do the tailpipe section as well.
If you want to custom cut a y pipe and feed into a large single in single out muffler than I would call a few muffler shops and shop around a few quotes.
I was quoted 700 bucks for that..and its only 250 for the oem muffler and tailpipe...
i might just buy them and do it myself....
I will do some more shopping around before making a choice.

canucklehead

Okay. I got my new muffler, and it is a Magnaflow aftermarket unit. Its welded into the factory setup of two pipes in and one pipe out.
It has improved breathing, and I notced a bit more oomph. My old muffler clearly was clogged so anything is bound to feel better.
I don't however like how much louder it is.
It sounds cool while flooring it, but the 1500 rpm sound where you are cruising around town in is too deep. Like a subwoofer turned up too loud.....
I'm sure that the cavernous space in the back of the van is not helping as the sound resonates around in there.
I would strongly recommend that you don't go crazy with your exhaust....unless you take steps to ensure the noise will stay the same...
I may have to have a resonator installed after my muffler to quiet this thing down.....

doordoc35

thanks for the reply, which magnaflow model# is it.it must feel alot smoother though,I decided to have a shop cut in a dual in dual out,i have dual cats and one single stock muffler now but i don't want it too loud either,i thought magnaflow was quiet?let me know if u decide on a resonater and how it sounds after (if so),im not sure wich brand muffler yet.

canucklehead

Weigh the price difference for the dual in dual out vs single out. You may have to go smaller size pipe on the dual out, vs. a single out that is larger and would be the same flow overall. There is only so much space over the axle.....two pipes may be too much trouble for little or no benefit at all.
I don't know what muffler model I have.....It seems a bit quieter the lat couple of days....either I am getting used to it, or its better when broken in......don't know.