If going from the 4 pot to a v6 do you need to use a different gearbox/bell housing or are the bolt patterns the same? We don't get any 4x4s with the VG series engines in only the 300ZX as far as I know over here, but it would be worth doing I'm sure as long as the gearbox isn't a problem. Whats the situation with the sump is it the same in the 300ZX?

On US models, V6 trucks use a different transmission and Tcase. The trans is totally different. The Tcase is the same case but with a higher spline count on the input shaft (30 vs. 22)

I'm sure the wiring harness is also totally different, as is the ECU.

Thanks for that, not quite sure what you're saying about the cases - might just be an anglo-american language mix up, over here we call the bit with 5 gears in it the gearbox, I think its just the transmission over there (might be wrong) and then the part that selects hi/low and 2wd/4x4 is the transfer box. With that in mind which bits are different.

If its just the input shaft splines can that not be overcome by using a different clutch plate?

Electronics/electrics wise I'd be looking to take the engine loom and ECU from the donor vehicle or fit an aftermarket ECU, Megasquirt etc

The transmissions or gearboxes are compeletly different. You would need a v-6 gearbox. The Transfer case that bolts up behind the gearbox with the low and 4x4 gears has a different spline count for the 4-cyl and v-6, but it is easy just to get a gearbox/transfer case out of a v-6 since most auto recyclers over here sell them together when you specify a 4x4.

Gearbox = Transmission
Transfer box = Tcase

Thanks for that folks. Short of having stuff shipped over from the states it looks like I'll hve tostick with the 4 cylinder then - doeas anyone ever convert the 12valve KA24 to 16valve version - (can't remember its engine code) - we had them in the 200sx (S13) IIRC

The KA24DE 16 valve twin cam would bolt in with the approriate wiring harness and ECU.

Is it worth the work? There more power fromn the 16valver I know but how is it for torque lower down, anyone fitted one for wheeling?