The Dominator idle circuit is silightly different than the 4150 series in that..

1. Trasfer slot is not visable at curb idle below throttle blades. (not all models, but most dominators)

2. idle discharge port is larger than most 4150 carbs

Whith this in mind.

I believe most of the air supplied to the engine at curb idle follows this path.

vaccuum is at plenum of intake manifold (via starter turning engine over)

Air is pulled through the idle air bleed.
Down the idle/transfer discharge channel where it meets the intersection of the idle jet fuel well ( or the brass idle tube discharge) this is where the air/fuel velocities are very high. This intersection is about .5-.75" above the fuel level in the float bowl. pressure here is very low ( high vaccuum- much higher than the intake plenum vaccuum).

Fuel is pulled via high vaccuum through the ifr, where it begins to atomize.
This atomized mixture continues until it meets the idle mixture screw.From ther it enters the idle discharge port as a high velocity properly atomized air fuel mixture into the intake plenum.

Most of the curb idle air comes from the idle air bleed and not the slight opening of the throttle blades.

.....So does the engine die with the idle air bleed cloged because of lack of air? or lack of fuel? .......

For argument sake ( a dominator with the throttle blades completly closed, and the idle air bleed capped) I do believe a stream of fuel is pulled from the idle discharge port in a continuous stream of raw un atomized fuel into the intake plenum . however there is no air. engine will not run or start.Try to cheat and open throttle blades to add air and vaccuum signal drops off and no raw fuel delivery at idle discharge port.