don't know if this will help but it's worth a try. mine sat for 30 years but was not stuck. i took the plugs out and poored a quart of power steering fluid down the intake. (any thing light would work just so it seeps into the rings) and then filled each cylinder full with a small rubber hose to make sure it was in all of them. maybe try that and let it set for a bit. then try moving the truck in gear like was suggested before.
