Technologically, the YF is slightly superior to the W-1; however the W-1 uses a leather (totally impervious to ethanol) accelerator pump whereas the YF uses a neoprene diaphragm.

Either (opinion) are VASTLY to the Rochester B of any year.

This link may help you identify the W-1, if not give me a call 573-392-7378 (9-12, 1-4 Mon-Tues central time AFTER the first of the year). For the first time in almost two years, I am enjoying family in person.

Carter Chevrolet W-1 carburetors

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