well iv been looking around at exhausts for my NNBS and I had contemplated getting a duramax exhaust with a new muffler. I want a 3.5" since i will go to a cammed LY6 once warranty ends at the end of 2012. I stumbled upon MBRP who makes a 3.5" exhaust for the NNBS 5.3. I can get the aluminized for around 290 shipped. I don't need SS since i live in South Texas.
Anyone ever run one, im looking for something economical and free flowing.

http://www.4wheelparts.com/Performan..._pn=MBRS5036AL

 

It says in the product description that the pipe size is 2.5" and the tip is 3.5...I'm running a single 3.5" system on my 04 SSS that I had custom fabbed at an exhaust shop with a 5x11x22 magnaflow 3.5" si/so. I'm not too impressed with the way diesel mufflers sound on gas trucks, they are very free flowing though.

 

I had them make me a cat back ss dual exh for my 5.3 Colorado.
looks,sounds and runs great. love it.

 

welcome to the site. now go to the new members section and let us know more about your truck.

 

On the MBRP website, it shows 3". 3.5" is used on their sierra denali system though.

 

ya i called and they said that this year they switched to 3".
but there are some 3.5" kits still floating around. those are the ones im lookin at.
i think even the denali kits went to 3" tubing this yr.

 

The description in that link says tube size is 2.5 and the tip size is 3.5, but the info box refers to 3.5 i/o? That's a little confusing unless I'm looking at something wrong...

 

Just a company that is just selling the product and doesn't know anything about it.

 

yup thats exactly the problem. on autoanything, when i look up that item # it still says 3.5". Idk but i im going to have to call up some companys before i place an order. I definately want the 3.5" tubing. even if i have to order the denali version.