When the truck is cold before starting, open the throttle so the choke sets. It should close against the airhorn and when you tap on it you should hear a slight snap as it closes back against the airhorn. Then take the vacuum pull-off hose off and push the choke pull-off in (back towards the chamber). This will show you how much the pull-off is opening the choke. The amount it opens the choke plate should be just enough to get a 5/16" drill bit into. The other adjustment to check is the fast idle speed. This screw is on the passenger side of the carb and down underneath the choke arm. Once the truck warms up you should be able to tap the throttle and then the idle screw on the drivers side can be adjusted for the idle speed. Good Luck Don