The Holley 1931 carburetor is a one barrel downflow type of carburetor. The carburetor is a one piece main body and throttle body casting. The 1969 model had limiter caps installed over the idle mixture screws so that they weren't tampered with. These can be removed, although I'm not sure about California cars. Cars in this state are under some pretty stringent rules. The 1931 was used on American Motors 1964-68, 199" and 232", 6 cylinder engines. The Holley carburetor number and perhaps the American Motors was stamped on the top of the fuel bowl. Holley carburetor numbers are usually something like R-3966-1A, but you will not find this on the carburetor. R simply means carburetor, The A means assembly. The -1 means it was modified from the original. For example they may have added a vent to the float bowl. Anyhow the list number in the above example is 3966 and will usually be enough as far as finding the correct carburetor parts. The Holley 1931 can have one of two accelerator pump diaphragms. One has a round stem and the other is a flat stem. The flat stem diaphragm has been discontinued (and we bought what was left), so we have a limited number of kits with that particular diaphragm. You can determine which one was flat by simply looking at the stem where it comes out of the carburetor bowl.
Free Holley 1931 Rebuild Manual - 1968-69 - loads slow
Holley 1931 float should weigh 12 grams or less.