Can't see the gear ratio well (under the bolt head) and bent, but looks like 3.27. I'm assuming this is a Automatic car.
It's also an 8.8, with limited slip, and a build date of Feb 5th, 1986.
3.27's were available as an option with AOD cars, and uncommon. Most came 2.73's. This is assuming nobody has changed the gears since new