Mike - the last W-1 most would be familiar with would be the 684s, used on 1949 passenger, 1949 truck, and some 1950 truck.

However, the very last W-1 was the 747s which was used by the US military on a Chevrolet 1 1/2 military only truck. This truck has a 235 CID engine.

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