Got an 83 Ram Charger with a 440 today!

I have attached two pictures of the pump with its small block brackets still attached as well as the pulley.
The dat pad on the front of the block said the following and I decoded it accordingly, 6T440 TE (at top of pad) and 12 3 (at bottom of pad).
6= 1976
T= Trenton plant
440= eng size
T= truck
E= cast crank
12= December
3= 3rd of month

Also got the following cast numbers off of the passenger side/bottom of the block; 9 25 75 (first line), 4006630-440-7 (second line), and just below all this was, DN. Any ideas what all this means? I'm thinking the block was cast on Sept 25, 1975, and was then assembled 3 December 1976? The guy said it came from a 77 motorhome.