I would have to find my hand written notes but I would think the best way to figure it out would be setting up with a pressure gage and testing pumps. My very old posting talked to the various # and stamps on the pumps, but no one could provide any decoding.

The Valve is custom fit to the pump body. Supposedly your not suppose to swap them by tech documents. When I was doing this I had a pile of pumps to sort through.
Here is pump data from one that I rebuilt and retained as a spare for my car.

8D8 8 B 2591C
1.387” Short Valve, .974” spring, and 4 .060” Shims

There were differences in valve length, spring and # of shims. A rebuilder would be able to modifiy to the pressure needs of the car. Could anyone decifier 8D8 8 B? Is 2591C a date code and shift, probably. Could some of the pumps I look at have additional stamping from a rebuilder? Possibly.

I know the charger hemi guys have assembly prints for the cars, does some one have assembly prints for the TA/AAR. If so, does the sheet for PS show any notes that could help with paint mark, stamp code?