John,
Do you know what Z's came with the r200 3.9 ratio stock?
After a quick search I have found:
80 280ZX MT, 4 seater or GL
81-83 280ZX MT (I believe this is non-turbo only, but the listing I found didn't state this.)
87-89 300ZX Non-Turbo
I can't seem to find the ratio for a '77 2+2 online, but have access to one locally if it doesn't have the 3.54 like the other 280z models.