Just found a 40" long muffler.
Muffler 4" In 4" Out, M085171, Donaldson
•4" Inlet ID
•4" Outlet ID
•8.5" Body Diameter
•40" Overall Length

 

Looks like a school bus muffler.

See if they will give you details and/or pics of the internals.

 

Looks like they specialize in big diesel rig stuff
Replacement Parts for Exhaust and Emission

 

Yep, and I believe Napa has Donaldson stuff. Still want to see what the guts of one looks like.

 

found these online





sounded like **** on youtube.... im still thinking to go with with the 30" case magnaflow personally.

 

That looks very close to what I already have. I don't think it would be much of an improvement.....

Thanks for posting that up!

 

Most of the 4" exhaust Ive heard or read about on here are on cammed/blown applications. Is anybody running one mostly stock?

I ordered a MBRP 4" mandrel bent tailpipe and 3" Magnaflow for my truck. Magnaflow is here, tailpipe should be here this week.

 

Are you lowered at all? I have issues hitting my 3.5 pipe with the axle and it is tucked up as high as it will go

 

I had 2" drop shackles, but Im back at stock height and I dont plan on lowering it.

 

I will be NA application, with 4" exhaust. Ill prob add a really nice big cam here shortly. 3" collectors, 3" ORY, into 4" Magnaflow 30" case dumped directly at muffler. Not necessarily a full 4" pipes, but the 4" muffler will be dumped. I may add a 4" resonator after the muffler, then dump it after that, if its too loud.