I haven't fully traced through the carb circuits yet. Is the pilot screw an air bleed screw (shutting it down decrese air entering from the air bleeds, thus enriching the mixture , or are they fuel limiting screws, controlling the amount of fuel going through the slow jets( shutting it down decrease the fuel flow, thus leaning the mixture?
fuel circuit only, no air bleed adjustment, as far as I know carbs w/air bleed screw adjustment were phased out industry wide back in late '69. air flow is controlled by the constant velocity slide.