/6 sitting up for several years what to do

If it is gunked, pull it out. Years ago, I got such a deal on a Pontiac T/A that I bought it, to give to my son. Put cleaner in it; the gunk when down and clogged the oil pump screen, spun bearing. And 10 years later, I do the exact same thing to a Bronco. I am an idiot, learn from my lessons.
Take it apart, clean and check.