I was running the stock exhaust sans muffler (which I thought was loud) and I can tell you one thing....4" straight pipe is LOUD!
We installed the MBRP 4" stainless exhaust last night at Mass Diesel. I asked Scott if he had a piece of tubing that would could go in place of the muffler, he said yes.
A little bit of fab work and straight pipe is in. Man is it loud...sounds awesome, but did I mention it's loud?

 

Yes,

I did mine about 6 weeks ago-Loud. Loud enough that whenever the PD is near me I drive like a VERY OLD lady!!

 

did mine yesterday also. just love the note when passing 2400 rpm on 5x5 full fuel

 

give 5" a try...

straight pipe is the way to go no matter the diameter...

 

I kno i thought my 4in was loud till i got stacks

 

Ive been thinking about straight piping for a while for my first mod. I want to have that loud sound I hear all you guys rave about. My only question is when you bring your truck to get it inspected and such does it present a problem??

 

no inspections in Kansas

 

I'm not due for an inspection until January, and then I'll bring it to a shop that I know.

I know a few shops in NH too, let me know when your going and I'll reccommend a couple of places.

 

Alrighty , the truck isnt due for another year. I'll deff have it straight piped by then!