This can be an expensive exercise (I just did it but at mate's rates). Gearbox is different, tailshaft, brakes, wiring loom. Many will advise against it as the cost will be the same as buying a GTST (take the body kit off of the n/a and put it on the GTST). I did it as the standard GTST would not have met my requirements. I would have changed a lot of things anyway (turbo, ecu, intercooler). I didn't put a turbo on the rb25de as I believe it wasn't strong enough so I sourced a rb25det. This probably doesn't answer your questions but might give you something to think about.