I replaced my stock setup at about 108k with a flowmaster 40 and custom bent 3 1/2 inch pipe. I also have an Airaid cold air intake and, between the two, have a great sound, better peformance and overall good response.

The exhaust cost me just over $300 in NH. I have a single pipe (no duals) and only modified the exit to keep the exhaust from coming back toward the truck.

Overall, it's been a good upgrade and something that I almost wish that I'd done a little sooner - if only for my ego.