hey everyone ive got a 75 280z with a 5spd not sure if thats an original but anyhow. i wanted to ask you guys how to check for which differential i have r200 r180 whatever. cuz i have no clue and knowing would be helpful. thanks. late.

see attachment

well looks like i have the one on the left so r200 which is what end ratio 4.11 or3.9 anyone know?

TO DETERMINE THE RATIO (internally)

If you're not sure which ratio R200 you have lying around the garage, check it this way:

Remove the rear plate (drain the oil of course). Then rotate the large ring gear until you see some numbers stamped into the edge facing you.

If it's a 3.54 it will read "39:11"

If it's a 3.70 it will read "37:10"

If it's a 3.90 it will read "39:10"

If it's a 4.11 it will read "37:9"

http://geocities.com/zgarage2001/engine.html

scroll down the page till you get to the part about diffs.

I thought they had 3.7 or 3.9 in the 260/280Z, though that site recons it would be a 3.54:ermm: