Another carb identification

Yep, that's not the original carburetor (or the original type of carburetor) for your '73. The first-year (1974) 1945s were troublesome; by 1976 or so they'd gotten better, but they were still jetted very lean to squeak the cars past the Federal emissions type approval tests so the cars could be offered for sale. If you are trying to buy a "remanufactured" carburetor you are about to embark on a money-wasting, frustrating venture that will end only when you stop expecting a "remanufactured" carburetor to be anything but a doorstop.

Carburetor operation and repair manuals and links to training movies and carb repair/modification threads are posted here for free download.