Nice solid looking truck.If it sat for awhile you most likely have a carb float that's ruptured if brass or absorbed fuel if the foam close cell type and has become too heavy.Another quick and easy thing to try is pinch off the rubber line fuel or remove the line at the inlet at the carb and plug it. Run the carb dry,until it dies then reattach the line and fire it back up. If there is a speck of dirt in the needle and seat this will many times flush it through and may solve the problem. Truth is you couldn't find a much simpler carb to rebuild.