Yeah, they do, on the '64-up Holley 1920. That washer is what nudges the bowl vent operating link to open the bowl vent when the throttle lever returns to idle. Speaking of the throttle lever, the one on this carburetor is bent so what's meant to be the curb idle screw contacting the carb body ahead of the fast idle cam is instead contacting the fast idle cam, and what's meant to be the fast-idle screw contacting the fast idle cam is instead contacting thin air aft of the cam. Grasp the throttle lever with suitable pliers and bend it back the way it's supposed to be.
Carburetor operation and repair manuals and links to training movies and carb repair/modification threads are posted here for free download. Tune-up parts and technique suggestions are in this post. If you're going to pick an I-guess-that's-about-right ignition timing setting, use 5° BTDC.
