1984 Dodge Ram truck won't start

Engine problem
1984 Dodge Ram V8 Four Wheel Drive Automatic 200k miles

drove this old W250/318 beast from indiana to georgia, ran great! Parked it for the summer, after which, it wouldn't start. Determined no fuel to the engine, replaced the mechanical fuel pump, finally started. Ran great for a month, then parked it again for about three weeks on top of a hill. Started it up to put it in my garage, on the way back down the hill in 4wd-high, it started sputtering. By the time I was on the flat driveway, the engine died and I have been unable to restart. Replaced the fuel tank, fuel filter and some lines, believing there was a clog; no change. Electrical is good, engine cranks, fan turns, but it won't catch. Tried starting while oil filler was open, saw the arm inside move. Pouring gas directly into the carb has long been a cold-start method, but now, even that is ineffective. Thanks!