Will I learned today the Z31 VSS does fit but its mechanical so I guess imma try Courtesy Nissan Texas to see if they have the NISMO 17t pinion available, its shows that it is for S13 but for S14 mostly all pinions are NLA.
Also the Z31 pinion is not removable, I tryed its totally different than that of the S13 pinion.
Pics:
http://www.courtesyparts.com/nms/s13/s13_4.html