I have a friend that has an 08 F-350 DRW 4x4 with a 6 speed. He told me today he was going to get a chip to get a little more power and better furl economy. I told him he wouldn't gain any mpg's unless he deleted the DPF. My question is, is the DPF bolted in or welded in and what companies offer DPF delete tunes? He will probably only want a tow tune since he pulls horses a lot. He likes to buy stuff before he researches it very well, :doh: so I won't have much time. Any help and suggestions would be greatly appreciated.