Randy, That Rochester could be as early as a '58
model because the throat is a little bigger then earlier models. It is a Monojet. I have one with the same number on my bench right now. The rebuild kit I bought from a local parts store is as follows: HYGRADE CARBURETOR REPAIR KIT #123A for Rochester 1 barrel Carburetor Models B,BC,BV. Perhaps this info will up you and your parts guy. Automatic chokes appear on early Chevy
cars, my '55 for example, so it's likely from a car, but you can change it over to a manual choke if you have to. If you don't have a manual choke now, buy a kit to put one on but you will have to remove the thermostat cover and take out the spring to operate the manual choke correctly.
