The plant where they were put into a car on final assembly?

Or the subassembly plant were the actual drum to drum rear end was assembled and stamped with the identification number?

The rears are obviously swap meet items. Just showing examples of application variability in the stamping.

same font of stamps on that part of housing show across body styles and final assembly plants. Not saying they were all the same. It's not like one place just made E-body 8 3/4 and not for other body styles.