You can hit 400 easy if you have a Phat Bank account.... ITRs pull 477hp
With a Good Turbo and Intercooler youll be around 250-300 im guessing and do H/CAI/Full cat back/Cams/ECU/wires... Basicly if you upgrade al thestuff you could make 400+hp P.S f you gonna do all hat Upgrade the Tranny(GSR trans) and get some aftermarket Rims w/ Hi Po Tires (Yokos

..... Short Throw Clutch would be nice too.....