i was looking at my rear end (type o) today after changing the gear oil that looked like it hasnt been changed for 40 years. it looked like nobody has messed with the gears and i counted the teeth on the ring(39) and pinion(14). then found these letters and numbers on the axle.
SA
-177-
394139
CFD 8

can anybody tell me what they mean?

 

39 ÷ 14 = 2.785 = 2.79:1 rear end gear ratio.

Norm

 

does anybody know anything else about the other numbers?

 

Probably just casting numbers that tell you where/when it was cast.