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If you are asking for help in identifying if it is an 8.5" rear or not, I'd need to see more of the housing.
Does it have a boss on the top of the center section for the brake hose? If so, that points to 8.5" 10 bolt.
Are there two parallel ribs on the sides of the center section?
What is the casting number on the snout area of the center section?
If you're asking to identify the carrier, gear ratio, or something else, you need to ask a specific question.
If you want to know the gear ratio, rotate the Ring Gear until you can read the stamped legend(s) on the outer edge. They will tell you the tooth counts and therefore the ratio. There is good info on ID'ing Olds differentials at this link at Supercars Unlimited.
Trying to determine if it is a 8.8 or 8.2 housing. Do not care about ratio. It has a cover like an 8.2. It has the square lugs on the bottom of the center section like an 8.5 I have asked for more pics and casting numbers.
