[piecesparts]

You do not have to connect the manifold vacuum to the ports on the carb to get vacuum to the distributor. The carb is the source of the vacuum to the dizzy, through orifices built into the carb body. You just have to pick either the timed port or the open port as to how fast you get vacuum to the dizzy dash pot. The adjustment of the idle screws using a vacuum gauge is the most efficient way of setting the fuel mixtures. When you connect the gauge, all you have to do is connect it to the intake manifold at a vacuum source and adjust the screws to get the right idle mixture and speed settings. My truck is connected to the open port and not the timed port due to my setup on my distributor springs and weights. If you are mostly stock, then the timed port is what you want. Cap off theother port if you are not using it for something.

The Edelbrock and the Carter AFB model carbs are EXACTLY the same carbs, with the same parts, just using different part numbers to make it look like they built them in different factories. Parts from one brand works in the other. They are built by a company called Magnetti-Marelli.

Set the idle first with the vacuum gauge and then wait for a cool evening or morning to get the choke spring to cool and set the choke plate for actuation when you push the throttle pedal down one time. Make sure that your electrical wire to the choke is on a ignition triggered power source, so that it starts to heat the choke spring when you turn the key on.

I set my idle speed, when it is on the choke about 1200 RPM and that is when it is on the high cam point of the choke rod cam. (the cam is on the driver's side of the carb down low and the idle speed screw sets against it) That way if it is not too cold, then it hits and idles at an RPM just a little lower than that.

If you have run your engine for a good amount of time and the electric wire to the carb is on at all times while the ignition is on, then the choke should be open. After you turn it off, it will take a while to start to go in the closed direction as the spring inside cools. If you do not push on the throttle or move the throttle in any way, after you turn the engine off, the choke plate will stay open due to the set screw sitting against the cam lobe on the side of the carb. When you push the throttle back, then the spring will snap the choke plate towards the closed direction.