Apples and oranges, however:

My Ford van 300 CID 4 speed 400 CFM Carter AFB on Offenhauser intake consistantly delivered about 40 percent better fuel economy plus more torque than Dad's factory fuel injected Ford van 300 CID automatic. Probably some of that could be attributed to the 4-speed versus automatic.

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