No compression in one cylinder

351m. Idles perfectly. Or what I can imagine. Did compression only on passenger side. Stopped after last cylinder. From front bumper to firewall, (not knowing which cylinder is which) 110-120-88-0. Same line up the 0 cylinder was the only one that did not have an oil soaked plug. It looked almost brand new. As I got closer to the cab each plug was less soaked in oil than the previous. Everyone keeps telling me all sorts of things and I do not want to tear it apart if I can help it.

Was guessing a stuck valve so I went and got some sea foam. Put can in crankcase and can in gas. Started it up and let it run. Noticed on the valve covers one side has an oil cap with a bad PCV valve other cover opposite end has some sort of cap. Never seen it before. Coincidentally enough the oil cap does not require the PCV the opposite side does. (Per Haynes manual for year and motor). Let it idle for a good twenty minutes and the top radiator hose did not have any pressure. Popped off the radiator cap and it was smoking slightly. Like it was coming out of the cap looking thing