The Carter YF was released in 1950.

Carter did release "replacement" units to replace earlier carburetors.

The last production YF was 1982.

The YF was modified and became a new model, the YFA in 1975. YF's and YFA's were produced concurrently from 1975~1982. The YFA production was continued through the 1986 model year.

Jon.

Good carburetion is fuelish hot air
The most expensive carburetor is the wrong one you attempt to modify.
If you truly believe "one size fits all," try walking a mile in your spouse's shoes!
The Carburetor Shop