Need advice on tuning 600 edelbrock carb- Have a 360 with 290 dur .500 lift, and performer rpm -around 10inHg at idle. Problem is that i have to set the throttle plates at such an angle for idle that they are clear past idle curb discharge and transfer slots. It will idle but the idle air screws have no effect on idle a/fr - and will somtimes pull fuel from boosters causing a fast idle effect. I have heard of drilling small holes near idle air dicharge -- to allow for more air and less throttle plate angle. I would think this would still pull fuel from the boosters to some effect. I have run mainly 4 corner idle holleys in the past and have not had so much trouble due to the fact you can adjust the rear throttle plate position too. Any info on modifying the idle circut would be a big help.