carb question (Holley)

Set the timing FIRST before you waste any more time! Do you know what the initial timing is set at right now? It's going to go down as you reduce RPM is my bet. I'd get it started and crank a bunch of advance into it and start turning the idle down.

Even if the PV is blown, at idle it SHOULD NOT have enough air flow through the venturis to pull fuel from the boosters... PERIOD! That circuit should not be active at all at idle. That indicitive of the throttle plates being too far open at idle.