If it can be assumed that it's jetted correctly, first make sure the timing is set properly. Then with the engine warm, roughly set the idle speed with the screw on the left side of the carb before adjusting the idle mixture. To set the idle mixture you'll need either a tach or a vacuum gauge unless you have enough experience to do it by ear, most don't. Slowly turn one screw in until the idle speed or vacuum begins to drop, then back it out a whisker. Repeat with the mixture screw on the opposite side, then do the whole thing over again. You're looking for lean best idle, meaning the screws are turned in as far as they can be without affecting idle speed or quality. Then set the idle speed where you want it, if it's a big change recheck the mixture again. When the engine is started cold the choke should/must be closed and will be partially opened by the pull down as soon as it gets vacuum, set the pull down to achieve an opening at the top of the choke plate a little less than 1/4" as a starting point. It wants to run fairly smooth and not stall after a cold start. You'll probably have to tweak it a few times after some cold starts to get it where you want it. Most Ford fast idle cams had 3 steps, the 1st step is where the fast idle screw sits when you depress the throttle with the engine cold and the choke closes, once it starts, the pull down will cause a properly adjusted cam to drop to the 2nd step. The second step is where the fast idle speed is set, with the engine warm try about 1500 RPM and see how it works for you on a few cold starts. If it seems to be racing slow it down a little, if it runs rough and/or stalls, speed it up. Don't expect to get it just right the first time.
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