Rear End codes... what gears?

Hello, I have recently realized (when going to change the diff fluid) that low and behold, my 84 GT Mustang has an 8.8" rear end! Previous owner must have swapped one in. I looked at all the numbers and what not on the tag on the pumpkin and here they are:

I am wondering what gears this rear end has in it, if they are in fact stock. I tend to believe that it has the 2.73s just because of the acceleration the car has (or lack of, I suppose). Can anyone tell me what these codes mean? Thank you for any information you can provide.

Timmy