You are right on the money, Peshman.Rough idle till it dies sounds like a fuel control problem. I believe it's carbureted.
1. Fuel pressure too high.
2. Carb float level too high.
3. Carb inlet/float valve leaking.
Either way, too much fuel in carbureter delivers too much fuel at idle and the engine can't burn it all. Can you actually smell fuel in the oil on the dipstick if you move away from the truck or is it just a strong smell of unburned fuel in the exhaust from running too rich? i would check the carbureter first. It's easier than pulling the intake manifold.