"i thought maybe it was the fuel pump, but it looks newer. after letting it sit a day or two i disconnected the fuel line from the carb, cranked it once or twice, and fuel was pumping."
You have had the truck for 4 years. The fuel pump isn't new anymore. Your symptoms are screaming "dirty check valves" to me.
Have you done anything to the fuel tank since you bought the truck? Your check valves may be gummed up from varnish in the tank being dissolved by 10% ethanol gas. Ethanol is an excellent solvent for varnish which would normally stay put on the inside of the tank if the old formula gas was still used.
Another possibility is that you may have a partial restriction in the fuel line at the bottom of the tank from debris settling there. This will make the fuel pump work much harder/longer to gas up to the carburetor.
Carl
