if you are using the GSR g/box it will probably go in n/p but check the length of the splines that go into the box. The issue is the bearing/stabilizer bracket that holds the left shaft to the block. (but you probably know that now)
It is easy enf to measure the distances that is required to go into the box.
you can change the bearing and CV joint over on the drivers side so the VR4 one fits to the box, but i dont think you need to? Only if you have LSD's does it become an issue.
thanks man, i just thoughtt there might be an issue strength wise, i used to play wit da 213/ s13's wen convertin a non turbo to turbo, heaps of **** kept breaking due to bein non turbo parts.