What rear end came in a 1978 280Z? Is it an R180?

I think the 280Z (1975-1978) used the R-200.

http://www.geocities.com/zgarage2001/z.html for more info.

We took a differential and mustach bar from a 1978 280Z and put them in a 1971 240Z. How can I find out for sure what differential was in the 1978 280Z?

I believe this to be correct

75-76 (3.545) (R200)

77-78 MT (3.545) (R200)

77-78 AT (3.545) (R180)

More here:

http://zhome.com/ZCMnL/tech/GearRatios.html