Got a question on the M4ME Quadrajet for 1981-86, or Edelbrock Q-Jets. These carbs have a little dome shaped bulge on the front passenger side. Inside of the carb next to the power piston is a little stop. If the carb were on the vehicle, the stop would be closer to you than the power piston. What do you set this thing to? Is this the Adjustable Part Throttle or something else? From what I can see, the job of it is to keep the metering rods slighty out of the jets to deliver a little more fuel. How many turns out should this be? I never see any mention of this on diagrams of Q-Jets, yet I've seen this on three of them, incluiding a Q-Jet I robbed of an old 403.