Anyone know anything about up-grading a diesel engine program? I got a 04 Duramax with Allison trans and want some more power. I pull a 28 foot 5th wheel and it does ok, but lacks a little on big hills and tight spots. I just got back from Myrtle Beach (600) miles of hard driving, and got passed by a few hot rods with campers. There are some programers out there that add up to 150 HP to my engine, I don't think I am ready for that yet. I know I will have to change exhaust and air intake for those. I was thinking about the ones that boost 40/70 HP.