Way more than I expected. We ran the truck at the dyno event in Missoula MT at Gomers US diesel parts. We took second in the event (lost to a 06 Dmax that did 719HP). We gained 102HP from last year just by adding head studs, main studs, fluid dampner, and changing smarty tune to level 9. I wonder what will happen when we add a modded CP3 and upgrade from a Fass 95 to a fass 150? After that run you could not get the grin off my face even now.