Truck Engine I brought home

[Ironrod]

I am attempting to start the truck engine; this is what I found to date. Starter was not turning over, found a bolt and washer in the housing. Cleaned the starter terminal and ground. Installed the starter, worked great. Then spun the engine over without the spark plugs to check for oil pressure, gauge showed 20-25 psi.
Things went downhill, zero compression on all cylinders. Hopefully it is just stuck valves. Next, remove the intake for valve inspection, and maybe get compression to attempt startup.

Happy Holidays
Bob