Looks like a 1959-1961 Iron cast T-10. Most valuable to someone restoring a vehicle from that era. They are not very strong especially when compared to later Muncies, Super T10's and Autogear 4-speeds.
A forum community dedicated to Chevrolet Chevelle owners and enthusiasts. Come join the discussion about restorations, builds, performance, modifications, classifieds, troubleshooting, maintenance, and more!