i just bought a 1991 z28 camaro with an automatic 305 tpi engine and a 700R4 transmission. i have not been able to figure out what the gear ratio on my car is. i am not sure if it has the 2.73 or 3.42 gear ratio. i was wondering if somebody could tell me what it is

What it currently has and what it came equipped from the factory can be two different birds:

https://www.thirdgen.org/1991-chevy-camaro

Here's how to determinne what ratio the rear is (jerk the diff cover and look--probably needs a fluid change anyway): numbers are stamped on the ring and pinion:

41 : 15 = 2.73
41 : 14 = 2.93
40 : 13 = 3.08
42 : 13 = 3.23
41 : 12 = 3.42
41 : 11 = 3.73

JamesC