Calling on Holley carb experts!!!!!!!!
The more you turn out the screws the more fuel, open the throttle plates with the screw in the right rear and you get more air, If it idles to high close the front plates a little. If you close the front plates all the way then turn the screw in 1 1/2 turns the t slots will be in the right place, start there and adjust the mixture screws.