dgrinnan, you could perform a quick test. With a cold engine, use the starter to crank and fill the float bowl, once you know the line and bowl are full stop cranking, don't start the engine. Leave the truck until the next day, remove the air cleaner, look down the throat of the carb, actuate the throttle rod and see if you have fuel by way of the accelerator pump. If the cold carb is empty in 24 hours I would suspect it is leaking. Just my 2c
