Howdy Back:
I know I'm a little late in responding to your query, but I'm still catching up from a trip to OKC earlier.
The term "Better" can mean many things. I can tell you that the cfm on a YF from a 200 is 187. The Holley 1946, used on 200 from '79 til the end of production, is rated (very optimistically) at 195 cfm. Both are complex carbs.
The Holley 1940 was a factory service replacement carb for when Ford went out of the Autolite/Motorcraft manufacturing business. The 1940 comes in many different version for many different years, for mechanical linkage or cable, with and without a SCV, and several different air cleaner mounts. The Holley 1940 was never used as a production carb on new cars by FoMoCo, to the best of my knowledge. In my mind, that would make the Holley 1940 a poor choice.
The YF became the standard 200 carb in 1970 and remained through '79. It would require conversion to a throttle cable linkage or modification to use your stock mechanical linkage. They do not have a SCV (to match the Load-a-Matic distributor) so would requre an upgraded distributor with the appropriate advance systems to match. It is a more complex carb than the Autolite 1100, with some advantages and some short comings. If you go with the YF it will take some time and effort to learn the nuances of tuning it in.
Hope that helps. Let me know what you decide to do, and what the results are.
Adios, David
