The 71-series gearbox speedometer drive works with the 1200 speedometer cable. If you need a longer cable, the Datsun 810 (200B) cable fits.
If the gearbox has an electronic sender for electronic speedometer, you can unbolt it and bolt in cable drive:
Cable drive (obtain from any 71C gearbox)
Silvia engines do not need the electronic speedometer signal. If it is installed, it can be used for overrun fuel-cut (increased fuel economy) plus the Silvia gauge cluster can be fitted to the 1200 dash.
See Main Article: Electronic Speedometer