I would block the trucks weight off the suspension so the springs 'rebound'. Get the wheels off the ground or removed so they don't flat spot, give em a good coating of protectant so they don't dry out . Get the fuel down to 1/8th of a tank of fuel and hit that with a bottle of standyne or ??. Change the fuel filter and cycle the treated fuel through the system by priming and running. Change the oil if it hasn't been done recently to get any condensation out.
Condensation can be unbelievable; I had a tractor stored in a dry hay barn for 10 years but it sat in a southern exposed window. The sun heated the tractor daily and humid air got 'pumped' into the crankcase. At night it condensed inside the cold metal. The condensation literally pumped the oil out and I drained out water! But I live in a rain forest, just keep the temp as steady as possible.
For that reason, don't start it every day or every week. I'd fire it up once every 1-3 months but get it to operating temp. This will keep the seals wetted and also exercise the valve springs. Cycle through all the gears and 4WD. Watch regularily for rodents, they can write-off a vehicle in a few nights.
That's all I've got for now...
