The Carter WCFB was produced from 1952 to 1967 and used on a variety of makes, starting with Buick in 1952. This was the first four barrel carburetor made by Carter; the name is an acronym for 'Will Carter Four Barrel'. William Carter founded Carter Carburetor in 1909.
WCFBs were used on several dual four-barrel set ups, such as the 1956-1961 Chevrolet 283, 1956-1957 Cadillac, several Mopar models and Packard. The small flange size (3-3/4" x 3-7/8") made it easier to squeeze two carbs onto one engine.
Carburetor numbers were found on tags. If the tag is missing, it can be difficult to identify the exact carb number, but in some cases there is a flange number that can help with identification. More information on Carter flange numbers is here.