Need Differential Advice

[M5Yates]

We let the tranny fluid get old and low on Grandpa’s 1954 3100 5-window. The transmission bearings let go. After rebuilding the tranny (3-speed manual), the mechanic inspected the differential and said it needs to be replaced. There are grooves in the gear teeth and the bearings are shot. He says that rebuilding the differential is difficult and it would be cheaper to replace it with a used unit. That would include the pumpkin and the attached drive-shaft.

This is a nice original truck with only 35,000 miles, but is there any alternative to using the diff from another ’54? Is a rebuild that difficult? (I understand that there are some leather pieces.)

Thanks,
Bill Yates
Austin, TX