exhaust help

[cherryred1500]

I have a 2010 1500 4x4 all stock for now I just received my 14 inch magnaflow muffler and I have been reading that the factory y pipe is very restrictive so I want going to order a new one through moes do I need the 2.5 in and 3in out ?

 

[jsteinm1]

That is correct.

It's not necessary with stock headers, those have more of a restriction. But it is a cheap part to change.