If they’re flat like in the pic I posted, those are likely “idle tubes”, like what are used in 3 circuit 4500 carbs.

If they’re cups, I’d just pull one out and see how the main well is configured.
Replacement plugs are readily available.

The “If it were me” answer is........ if I wanted to hit the easy button to do some experimenting, I’d just buy one of these and see what happened:
https://www.holley.com/products/fue...metering_blocks_and_plates/parts/134-155