The 2343 Santa Fe F3 B unit of the early and mid-1950s was produced to be used with either the 2343 or 2353 Santa Fe F3 AA diesels. When a 2343C is coupled between a pair of AA diesels, the end result is an impressive-looking ABA unit. The ABA lash-up was both prototypical and a common sight on US railroads during the 1950s and 1960s.
Externally, the 2343C followed the same manufacturing change as the 2343 and 2353 . From 1950 thru 1952, the 2343C had wire-cloth roof ventilators -- exactly as those found on the the 2343 F3 AA diesels. For its final three years of production (1953 through 1955), the 2343C had plastic ventilators molded into the body -- just as the 2353 diesel was manufactured. Therefore, if you are looking to match a Santa Fe B unit to an AA diesel combination, there is an early and late version of the 2343C. To this day it remains a mystery as to why Lionel changed the number of the AA unit regarding the ventilator change but not the number of the B unit!