I have a stock, original vacuum secondary Carter AFB on my 312 Fairlane. A while back I bought a correct '57 4100 to overhaul and use in place of the AFB, believing it to be a superior carburetor. The shop manual also references the first gen Holley 4150 as an option.

I was wondering, what determined which carburetor ended up on which car? Is one more common than the others? Did the customer choose between the 3, or was it a production order thing, or maybe by location?



1954 Crestline Victoria 312 4-bbl, 3-speed overdrive