I would definitely replace the fuel filter, and make sure the spark plug gap is set to .032". Replace the plugs with Autolite #64, or Champion Truck Plug #4404 if the plug electrodes are worn or rounded off. Replace the plug wires if the plug insulators are dirty, or if the motor is hard to start.
If this truck has a manual transmission; the carburetor idle mixture screw and idle speed screw may need adjustment.
If the truck cannot be adjusted to idle well; the ignition timing may have been adjusted without first disconnecting the vacuum advance and plugging the vacuum hose. That could make the timing come out too retarded, and would cause stalling. If the timing is set properly, and the motor idles roughly, adjust the valve clearances and then check the compression in all the cylinders. If any cylinder has less than 150psi compression; or there is more than 20 psi pressure difference between any two cylinders; the engine will have to be repaired mechanically to bring the compression up to the manufacturer's specfications.