Engines been sitting

If you plan on using this motor you probably want to tear it down for inspection anyway.
If you want to just fire it and see what happens it would suck to have a piston hit an open valve.
I personally have pulled valve covers and compressed the valves to see if any hung up, but that is a pretty sketchy way of doing it.

The guide seals are probably trash by now also.
Then you can shoot each cylinder with a little oil and crank it with the plugs out till you get oil pressure reinstall the plugs and see what it does.
You could also compression test it at this point if you wanted, but after sitting so long it might not tell you much that could be counted on until it ran for a bit.