Holley Street Avenger 570 Idling Problems

Jar of likely answers.I like that, and agree.
Still havent heard what youve been targeting for idle rpm.
-Post #5 spilled the beans, and Post#7 is a great plan.
-#5 says there is continuous vacuum at the spark-port.If you are sure you correctly identified the spark-port for the vacuum advance, and in fact there is continuous vacuum there, then the primary butterflies are definitely open too far.And ,yes, if you try to idle it with the v-can pulling timing in,adding some to the 14* initial, the engine might not like that.
-Post#7 should get results
-And Id like to add;
-We need to figure out why the primaries are open so far, and fix that.Cracking the secondaries can help, esp if they have their own adjustable idle circuits.But, like previous posters have said, its a small cam and we shouldnt have to resort to that.Is your PCV system hooked up?If no, Id start there. If yes, Id put a different timing lite on it and verify the 14* initial. If the 2nd lite says the same, then I would be proving the balancer mark.If all that checks out, Id go back and prove the float level isnt too low, which could make idle fuel pull-over difficult,necessitating the extra butterfly opening for the engine to get the fuel it so desperately wants.
-Post#8 below, triggered something in my sleepy brain cells.You might want to check at what rpm the mechanical advance starts coming in. It should not begin until a couple to a few hundred rpm above idle. In your case,say 1000 to 1200 rpm