Engine Help

[malihoochie]

It would seem to be vacuum leak related, especially since pulling a vacuum line and adding a leak doesn't affect the motors running. Putting your hand on top and blocking air only adds to this thought as it seems to be getting air elsewhere. Edelbrock carbs do not have many internal parts to fall, move, or break & the vent "tubes" are on the sides of the air horn - so a sudden stop (going forward) should not cause fuel to choke out the engine.
I suggest looking on the manifold for missing or damaged vacuum plugs, hoses, etc.