I am going to be in the minority opinion on this thread (see my comment about Shell Oil wink )

If one does the math, comparing the IHC 735s to the original 574s Chevrolet carb, one will find:

High vacuum (cruise) the 735s is 22 percent richer!
Midrange the 735s is 35 percent richer!
WOT (wide open throttle) the 735s is 28 percent richer!

Some of the engine gurus can advise better than I, but my guess is that kind of richness is NOT good for your engine!

I am sure finding carburetors for USA-produced vehicles is not easy in Wales, but I would suggest patience is your friend! I would look for either an original 574s W-1 Carter or the 964s YF Carter; both of which were specifically designed for your engine.

I do not think you will have an issue in disposing of the 735s.

EDIT: Do you know, or can you identify your W-1, and what might be wrong. Every single part for the 483s or 574s W-1's are readily available. If the casting are good, the carb is fixable.

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