Thanks Jon.
I was interested in learning what I would have to do in a similar situation as Tom (replacing 2X YF with 2X W-1).
Looking for used carburetors, I noticed that the correct models you need don't jump out and bite you on the leg. Searching required.
First thing is to look for a rectangular ID tag. The first carburetor listed by Jon has a tag but the others do not.
Second is the stamped number on the throttle base (picture) which are not visible in the ebay pictures.
Third is to visit (
https://www.thecarburetorshop.com/CarterChevroletW1.htm) and compare pictures and text description.
Look for 4-hole bowl covers, and 3-hole airhorns to quickly differentiate from the pre 1937 models.
I don't have a practiced eye for the W-1 but there is a visual difference between 1939/40 420S and the change in 1941 and after with the 483S/574S.
So looking at the carburetors Jon listed, visually they look like what I need but it's pot luck on their condition.
Buy 3 carburetors in hopes of having 2 good ones or maybe have one extra for spare? Couldn't hurt.
$85.00 + $22.00 Shipping + $80.00 + $13.00 shipping + $74.99 + $8.00 shipping = $282.99
Now I want matched carburetors. Both 483S and 574S parts are interchangeable. It sure would be nice to have two of the same model but...
I MUST verify that all components, jets, metering rods, air passages etc. are identical. Verify against my Carter W-1 spec sheet.
All of the above just to get to square one.
Next I have to check for worn parts especially the throttle shaft, check for warpage (shouldn't be any), buy more parts and repair.
Thorough cleaning.
Purchase carburetor 3 kits (Ethanol tolerant) and assemble.
Adjustments to spec (allowing for Ethanol gas).
Make modifications to the throttle linkage.
Adapt/modify fuel lines.
Attach manual choke and bracket.
Follow procedure for synchronization of dual carbs (
https://www.thecarburetorshop.com/Dual1barrelcarbs.htm).
Top it off with 2 new air cleaners or reuse the ones from the YF.
