I thought of something else you can check and reset if needed is the fuel, float level. Most Holley like and need the fuel to barely dribble out of the side hole when running at idle speed, if you look closely at your carbs you will notice that the outboard screws for checking the float level are higher than the center bowl is Don
t set them in the middle of that hole, that is to high
Let us know how your doing on fixing this issue, six packs rock when you get them right Which is not always easy