Best bet is to go for an r33 manual abs diff change the shafts etc is what I did with mine,or a gtr set up which is what I have now but they are silly money.
Your other option if you want to keep the helical rather than go to vlsd is to change the crown wheel and pinion for a shorter final drive but I don't know how much that would cost
Your other option if you want to keep the helical rather than go to vlsd is to change the crown wheel and pinion for a shorter final drive but I don't know how much that would cost