been dealing with duramax's for a long time now im tryn to help my brother out. he just bought an 07 mega cab short bed automatic 4x4 stock truck just has a cold air intake and the cats gone. dont have a stock file to build off of looking for help. hes looking for a single tune maybe 80ish hp just enough to help with towing and better economy. any help guidelines or examples are appreciated. will even trade a duramax file if you want lol