carb question (Holley)

That should idle EASILY at about 800-900 rpm without issue. What's the initial timing on the engine?

You need to figure out why the boosters are dripping. Float level, bad float. Try turning the float adjuster down 1 full turn and see if that helps. Give it a couple of revs to so float level drops and check for dripping. The dripping boosters are the likely reason the car won't idle.