the wheelbase is longer and the ass is a little wider, the doors are different and there is a back seat (obviously)
As to parts specific to the conversion, the tailshaft will be slightly longer.
Thats pretty much it.
Given that your probably going to have to get a custom tail shaft made up anyway, its really not a bid deal, you'll be able to use pretty much any RB conversion as a guide for yours.
for the transmission you have 2 initial choices. Either a RB25DE tansmission will fit between the gear box crossmember mounts in the tunnel with the downside of being weaker, so no good if your turbo charging it, or you go with a RB25DET box and modify the tunnel mounts, and then it'll handle the power. The DE box is cheaper, the DET box is pretty sought after. I have seen DE boxes selling for $300-600, whereas a DET box generally costs round $1000-1400
You may be able to fit a different gearbox, eg 300zx, Supra, S15 6 speed ect, but you'll need to investigate bellhousing adaptors, box strenght vs application ect
Before you source an engine you need to ask yourself a few questions.
1. Will it be turbo or modded for big power?
2. If your keeping it turbo, do you want a single turbo or twins? (leads into question 3)
3. Do you really want a RB26? Or will a RB25 tick the boxes? The RB25 can be found as a package a lot easier and more affordable than a RB26.
The RB26 will also require a new sump because the front differential for the AWD system is built in (same with the RB25 if you source it from a Stagea)
I would also highly reccomend keeping the stock ECU to run the whole thing, at least for the purpose of installation, inital tuning/bug hunting, engineering and rego.
It'll make emissions testing a lot easier to pass.
The ECU wiring loom is reasonably simple to isolate from the skyline wiring loom and set up as a stand alone system.
(any questions, hit me up)
Edited by nizm0zed, 16 February 2017 - 12:01 PM.