How to identify your zenith carburetor model

Zenith carburetors built from 1932 to about 1980 have a round aluminum or brass tag about the size of a dime riveted to the top of the carburetor.

The inside number is the Zenith assembly number and the outer one is the OEM number.

Later carbs sometimes have a stamped number, usually on the top part of the carb, or in many cases, an aluminum tag.