HOLLEY 770 wont idle down.

I had one other thought "T". If he's running a "ported" vacuum advance, and if the throttle blades are the culprit and are hanging open a little, that would throw the vac to the dizzy and make the r's spike at idle. If it is ported, you might pull the line and see if the idle comes down with that. It may confirm that the blades are open too far vs. a vacuum leak somewhere?