The sticky in this section on differential axle codes is incomplete. Spent the better part of the morning trying to decipher my axle code using the internet. 6PM as it where. Shows up no where. One thread had it identified coming off an 84, but I don't think they made disk brakes in 84. Confusion and desperation set in. Finally, I had the bright idea to check the parts book. There it is, 1991 3.23 posi, J65 brakes, just like the car it came from. Now it all adds up. (also good for a 1992)

Hoping this will save the next guy searching like mad a little trouble.

 

They did make disk brakes for the rear in 84