Reviewing this guide, it looks like a GM 55 passenger car rear end to me. There are other here who will know for sure.

https://www.differentials.com/technical-help-2/differential-identification/

Last edited by Gord&Fran; 11/10/2021 11:50 PM.

Gord 🇨🇦
----
1954 1/2 ton 235 4 speed