'57 'C' code Birds from the factory were equipped with only the 292 engine and that only came with a two barrel carburetor and a medium duty 3 speed only manual transmission. In '57, the 'C' code '57 'Bird was the least expensive base model 'Bird you could buy.
In '57, to get the FordoMatic or the heavy duty T-85 with overdrive in a 'Bird you had to step-up to a 'D', 'E', or 'F' code which came with the 312 engine.
Like some of you, I've seen numerous '57 'C' 'Birds outfitted with 292 engines and four barrel carburetors, 'C' 'Birds with 312 engines, and 'C' 'Birds with FordoMatic transmissions. None of these were originally offered or released from FoMoCo equipped this way. Not all 'Bird enthusiasts are purists!

Sounds healthy to me!
NoShortcuts
a.k.a. Charlie Brown
near Syracuse, New York