Truck sat for almost a year as I was saving to repair transmission...starter went bad, alternator followed shortly (thanks to mud wasps...) and now, my compresssor goes belly up. A sitting truck will fall apart if not maintained.
maybe a car cover while your at it? storing a car outside is rough, but lubing cylinder walls, fuel stabilizer, and an oil change is very beneficial, also maybe starting it without fuel to get oil into the important places? do a quick google search there are plenty of tips on outside storage.