In your 2nd sentence of the original post you say; "The truck runs fine but will not idle unless the choke is on".Then we talk about things to help overcome insufficient fuel feed to the carburetor.I think fuel feed deficiency that would effect idle could not allow the engine to run "fine" off idle.In fact my experience has been just the opposite that an engine experiencing insufficient fuel feed to the bowl would idle quite well but could not run when the throttle is opened.
Updraft carburetors are different animals when it comes to getting the idle fuel to the orifice at the throttle where it enters the airstream.The emulsion of fuel and air passes through the joint of the carb upper and the lower which contains the bowl, and sealing of the gasket at this joint is critical to the idle circuit.
Be sure the venturi has not been put in upside down.My picture shows the larger part of the bore toward the throttle plate.
Did you take the main discharge nozzle out when cleaning the idle passages in the lower body?My picture shows some complex passages in this area where the idle orifice tube is fed from the main nozzle area.
If it runs well off idle but won't feed fuel to idle the trouble lies in the idle circuit.
