The 1988 300zx turbo "Special Edition" or "SS/SE" came with a 3.7 VLSD R200. This may be the same unit as 240sx since it came with halfshafts exclusive to this unit. It was the rarest z ever made though, so it probly doesn't help you very much. Just throwing that out there. More info on this car here:
http://z31.com/ss/