1959 Other Chevrolet Models

Engine Mechanical problem
1959 Other Chevrolet Models 6 cyl Two Wheel Drive Manual

I Have Chevy truck that has not been running for a number of years and the engine is stuck. With out taking the engine apart is there some kind of fluid that can be put into each spark plug hole and see if that will looses the piston from sticking. It is a Chev 216 6 cyl. Will WD 40 work or is there some other product that could be used. This truck has been garaged since 1979 and was runnig at that time.