Yeah didin't a gts4 four door version 32 get made if so i couldn't imagine it'd not be to hard to source if no four door then just longer tail shaft plus i've heard that the gts4 had a taller ratio in fith than the gtr, more speed the better but don't know anyone in your state, have you got jap spares or sss automotive if so they'd know where to source box, diff, cradle, cross memeber if different and the rest if so i would imagine it would be a drop and play issue due to skylines being mass produced therfore mounts and bolt holes will be in your chassie but some thing you'd wanna make sure before hand cos if it's coming from a 2 door i couldn't picure there being mounts for the box and diff, if no to mounting and accessability of parts i'd just save my time,effort and money and dupm it something with a bit more hasssle free to it a gtr shell don't go for much if you can get the right one and it would be worth your time and effort the only issue is reistering due to shells being either raced or de-registered, un- registerable; imported shells for parts ect just do backround checks