GoGo87U

I fear that I hijacked an old post, so I am posting this anew.

My 1997 has an RPO sticker showing M30 (automatic) and GU2 (rear axle 2.73 ratio). Of course the gearing in the rear end could have been replaced, but that is not my concern in this post.

I see from the metal tag on the GETRAG differential case that the GM part number is 12554837.

My questions:

(1) Does my GETRAG differential serial # AHA 00134 reveal any hidden information? (ie: build year, build date, plant location, use designation)

(2) Does my GETRAG differential part # 625.0.0012.01 reveal any hidden information?

Specifically, I’m asking if any member knows how to decipher the GETRAG part numbers and serial numbers.

The serial number on my 1997 is AHA 00134.
Member DeBaGo had a 1998 with AHJ 00735.
Member ViperBlueLX had a serial number BJB 00200

Has any member decoded these alpha-numeric sequences for C5s?

Thank you!