I bought the center dump ones from Summit and my local shop said they won't work on my 2 WD. (I'll sell 'em cheap!)
X2
Except my muffler shop is me, and I fabbed together my exhaust, it works great!
Check this place out, if you know how to weld an exhaust system on one of our trucks is very easy to weld up.
http://www.gbemandrel.com/