Is there a reason why you want close to 600kW in a R32 GTS-t?
Have you thought about suspension work, subframe changes (from a newer car, offsetting it), diff choice, brakes, gearbox?
There's a high chance you're running a RB20DET gearbox which will not like close to 600kW being sent through it.
Also a 6262 won't get you close to 600kW.