Rick - Using the info from this Dana/Spicer axle identification guide, it could be a Dana 44. That's just from comparing the rear cover pics with yours, which are a little rounder on the bump out than the 50/60 series axles. The decoding info at the top of the page should be helpful, assuming you can find/read the stampings on your axle?
You are a wealth of information.
~ Rick
1947.1 GMC EC152 [228ci + 4spd] "Love at Last" Follow in the DITY 1968 Firebird [350-4 + th400] 2022 Tacoma I've been more of a car guy - but always wanted to get an old pickup
