The gas tank was empty or very near when I brought her home. I poured some gas into the carb, and the truck fired up fairly easily.
It ran off of the carb gas (pretty roughly) for about 15-20 seconds, and then died. Then I replaced the fuel filter and put 5 gallons of gas in the tank. Cranking won't it fire up. It occurs to me there is probably a mechanical fuel pump in this thing and that I need to pour more gas in the carb, and this should be enough to get everything flowing from the tank.