NOS 1931-47 4-speed gears, this is the old non-sycro 4-speed with the reverse lock-out lever that was used prior to the SM420

Gp 4.421 #501501 2nd speed gear
Gp 4.421 #501502 3rd speed gear

The only national GM parts vendor that sells these has them priced at $59.95 each.

I will sell the pair for $40.00 including USA shipping (small flat rate box)

These are in the factory GM boxes, email photo available

Contact me at: wd.fosterverizon