OK, first of all, the clearance is set by the spring/bolt assy on the actuating arm. The cams and their different mounting positions adjust the amount and rate of fuel delivery. It’s OK to have more than .015 clearance, you don’t do the tuning based on the clearance. You change cams and make adjustments to the spring/bolt to get the accel pump shot correct. Many times the pump has to be pre-loaded a bit. The pump shot should be instantaneous, as soon as the throttle moves. When you think you have it right, then make sure the clearance is at least .015. You can also adjust the size of the nozzles to help in tuning.
Chuck J.
64 Galaxie 390
68 Fairlane 289
