once you go over 350ish, you will need to upgrade the gearbox too, clutch, fuel pump, garrett turbo of some sort, larger injectors, FMIC, cold air intake, straight through exhaust system, im sure there is more
remap(ecutek/simtek)
decat downpipe
straight through centre section
uprated fuel pump
3 port boost solenoid
would probably see you to about 300-310 @ the flywheel
400 @ wheels would be about 480-ish @ the fly
Crazy!