Odd that no one has reponded yet.
I had a Holley that leaked like that and drove it for years so I don't think that is related to your problem although it is fuel related. I would start with the easiest and look at the fuel filter/air filter/choke setting. Then I would check fuel pump and carb.
The carb may have trash stuck in the metering plate/float bowls etc... Also don't rule out that you might have some bad gas in there too.
That leak is comming from the throttle plate shaft. The bushings are worn and it does cause a vaccume leak but I don't think it enough to stall you out, at least in my case it did'nt.