z3n2k is in the process of doing this conversion... Hes looking to push 350rwkw out of his 26 that hes going to drop in. For the conversion, hes spent buket loads! So be prepaired! Ie, 33gtst gear box, 33gtr diff, twin plate OS clutch, you will definately need to modify the drive line, ie the tail shaft is different aswell...
Best to send him a pm if your interested on the conversion... His isnt complete yet, hes still building up the motor and waiting to get a clutch, pfc and a few other bits and pieces, but should be a rocket once completed!