Truck had been sitting for quite a while. Anyone know any tips/tricks to free this up without having to pull the head?

 

With the valve cover off, soak the stuck valve with penetrant overnight, and making sure the rocker isn't touching the valve, tap it with a mallet, also you might try the rope trick in thru the spark plug hole and push up on the valve with the piston.

 

Thanks Bill!! Someone also suggested once out was free and running to run small amount of marvel mystery oil in carb with gas to lube valve stems from inside??

 

Don't know about Marvel but I would run some Seafoam in the oil and gas to clean it out.