ur gonna have to get some lower compression pistons, then ur type r motor is basically a b18c1 w/ a better intake manny. im not saying the type r motors aren't good motors, but the b18c1 is a better base. i've seen more power then 500 in a gsr, runnin in NHRA. but then they are hardly even a b18c1 OR c5 any more. the type r motors are great motors, an the only ones that show them up displacement wise are the S2000's. i kno the potential of the type r's, i race w/ a few of them on a weekly basis. they are all going for auto crossing which is wut the type r's are set up for.
with the price difference of around 1500 dollars, an 10k to spend, u could build the gsr motor to be faster then the type r motors. u do have to understand tho, that jus because they are type r motors, they aren't nessecarily the best for everyone (especially in this case).