What rear end gear ratio came in a 1990 camaro rs?

The 1990 Camaro RS could have come with a few different rear-end gear ratios, depending on the transmission and options selected. There wasn't a single standard ratio. You'd find ratios ranging from 2.73 to 3.08 to 3.42, and possibly even a 3.23 in some cases. To know for certain what ratio is in a specific car, you'd need to check the vehicle's axle code (usually found on a sticker or plate) or physically inspect the differential gears themselves.