The R33 GTR antiroll bar is alot thicker than the stagea one, but will not fit, incase you are tempted to try it, its very close though!
Also front R33 GTR shocks will fit but rears wont.
Ikeya Formula Lower arms for R33 GTR do fit though
I realise this thread is abit random, maybe a stagea mod, can change the name to what fits and what doesnt.