On a auto truck at rear wheels start with 200hp then add 80 to 90 hp for injectors ans about 45-50 for the box at peak hp, it will make 65hp difference at at a lower than peak hp range, so estemate about 325hp to 340 depending on the truck and the dyno. I have seen a 27hp difference on my truck between a dynojet and a Mustang dyno with the same settup.
Jared