if your looking for quiet y not look for a cummins stock muffler. since 04 (don't quote me on yr) they have been 4" stock.

 

I really need to get under there and measure to see how much room I am really working with

 

4 inch MBRP diesel cat back. the aluminum ones around probably no more than 300-350.

 

I have other ideas for the exit, just deciding on muffler first...

 

well the muffler is what i was kinda referring to, big and straight through design, you could go either 4 or 5 inches. find on that fits a 2500 your bodystyle and just hack off the rear for a dump at the axle.

 

I drove mine without any exhaust, open 5inch DP for like 3 months. DD, lol. I then drove it which an open ORY pipe, for probably 6 months total. Just put a stock muffler on it last friday, and its awkwardly quiet.

 

I think what he's saying Richard, is...suck it up and drive. lol

 

we all gave him hell on Jackson......

 

Hell my DD right now has an inspection from march lol, cause I couldnt get it inspected with no exhaust.

 

Finished the easy side of the cold side...

It looks pretty clean in person, air filter fits great right above it. There are a lot less bends involved than having the intercooler below the bumper.
Also replaced the coolant res. The stock one was pretty disgusting.