Holley 1920 issues

Hard to tell from here, but I would guess that the small air cleaners are not the issue..... unless you forgot to take the plastic wrapper off LOL. The engine should not be pulling huge amount of air at idle. BTW, have you checked the air cleaner base to make sure it is not contacting any rods and perhaps moving the choke rods and closing the choke?

First thing I would do is check the wet float level; it sounds it might be very high. Pull off the small triangular cover on the bowl for the power valve (economizer) and idle the engine. Use a small scale to measure how far the fuel level is below the flat area on the bowl where the triangular cover sets. It should be very close to the spec; that spec can vary per exact 1920 model. I have seen 11/16" and 27/32". It needs to be exact; look it up by the list number on your Holley 1920. The float level sets all other carb operations and is critical.