The R33 series
R33 GTS has an rb20e sohc 2 litre
R33 GTS25 has an rb25de dohc 2.5 litre
R33 GTS25t has an rb25det dohc 2.5 turbo
It will cost you a good deal of money to make the GTS25t match the GTR in performance. If you have it you can get good hp out of them though the blocks are much weaker than the RB26DETT and will crack.