Please help me identify this transmission

I am considering taking this transmission on trade.
The other guy says it is a Tremec T5 from an 82 pickup
(that's all I have to go on), but the bell housing is attached.
I thought all tremecs had separate bell housings.
I would need to acquire a new tail housing (among other things)
so identifying it is crucial.

Can anyone identify this? (See attached photos)