Damn man, i'd say 3 years definately qualifies for "long-term" storage!

No way i would have my 80 sit still for 3 years. Your best bet is to have someone responsible start it at least once a month and be aware of how to charge your battery as it will slowly die.
Ideally someone you trust should just drive the truck once or twice a month to get everything up to operating temp, to keep everything lubed and to maintain charge in your battery/s. I would also ensure the heater valve is cycled so that the whole cooling system is circulated and the A/C is used to stop the seals drying out. Good luck.