I had an R31 drifter with a RB20 turbo with the same clutch as yours, When the stock gearbox blew, i upgraded to one out of a R33 and the ratios and overall feel were so much better. Definately spend the bit extra and upgrade if you're giving it, the only problem i had was the speedo is different and i needed to use a speedo drive out of a navara or something.