How many quarts do I need for my differential?

[Fiat88]

Ordering some Red Line 75W90 Differential Oil, 1 Qt. from IAP, how many bottles do I need for changing the differential oil in my '79 automatic? Thx.

[velozi]

Mine took almost qt and half. Some late models take a little more. Buy two and you are ok.

I use the one from NAPA 75-210. Not synthetic but same thing and a lot cheaper.

[Fiat88]

Thanks ordered two quarts.