You have to figure out if the problem is fuel or ignition. Make the truck warm and when it won't start pull the fuel line to the carburetor and crank the starter while observing if fuel squirts out. Stop as soon as you are sure and be careful with this (fire extinguisher at hand). If you are getting fuel then check for spark at the points. Take the distributor cap off and turn on the ignition key inside the truck. Manually turn the engine until the points open. You should see a spark between the points. You can rock the engine back and forth a bit. You should see a spark when the points open. If you are getting fuel at the carburetor and spark at the distributor then the truck should start. At least you will have eliminated a lot of possibilities.
