cant watch, got dial-up, would have to shave twice waiting for it to download.

Look up somewhere how carbs work especially holleys, learn it yourself, its the best way, the physics is all the same, just the methods of control differs between the various carb makers.

You can see everybody has an opinion, just like o/ds and axle ratios-anyone with a keyboard can be/is a Goodwrench. Look at how Ford starters work after you twist the key compared to how GM does it. Bottom line they all spin the flywheel.

Saw just first 5 or 6 seconds, is it true it was idling at 1000 (+) rpm and at that point you are seeing the 23 inches of vacuum?
Your butterfly maybe positioned open enough to be idling on a good part of its transistion circuit (slot) thereby using up what is normally used for transistioning to the main metering circuit.

Ideally your idle would be maybe 600 rpm resulting with maybe only 19" vacuum (more normal reading), the throttle butterfly would be positioned just at or slighty below the transistion slot or passageway just waiting for the blade to open and allow manifold vacuum to be exposed to this slot so that this additional fuel passage way can spring into action providing, no, ALLOWING extra fuel to carry out its intended duty. If You choose to have this high of an idle and are using up the transition passage, then YES, you will need more acelleration pump shot to overcome (remember crutch) this man made stumble. (does it run on after you turn off the key?)

A stock cammed engine should not need a 1000 rpm idle if the carb is set correctly. Check out the Idle circuit section of a good carb book and look at where the butterfly is positioned-say maybe- the Doug Roe Rochester book. (dig-dig). These things were put in carb to improve drivability. Just wait till it gets really cold-what a bear!

You have a good text book problem, with many guesses offered as to why its there. This is an excellant challange to learn what is the prob. Once you get a good handle on carbs and really understand how they work, then fi/efi and how computers make them work will be a snap.