with gsr cams and that header, maybe 180-190whp.

with bigger cams like rm m22x and a decent flowing header like a rage and matching exhaust, 200whp is within easy reach. provided you have a good tune. and i hope you have access to nothing short of 93 octane otherwise that compression is going to make your engine ping like crazy. i would have used p30's or itr's for a more manageable cr.