Hi Doc,
I'd be more inclined to suspect a rod knock despite the good oil pressure. Obviously, the only way to tell for certain is a tear down. Actually, not a huge project. Pulling the engine on one these cars is relatively simple compared to modern stuff. You'll have to take off the hood, drain engine and radiator fluids, pull the radiator and then pull the engine. I've done it singlehanded in my late 60's. Be careful of the manifolds as they seem to be made of the poorest quality cast iron known to man. If you only pull the head and oil pan, you won't even have to touch them and so much the better.
On the plus side, you have acres of room on all sides to work on the engine compared to modern stuff.
Parts for the engines are still widely available and relatively cheap. Continental built these engines for many, many years and they were used in a wide variety of Jeeps as well as lift trucks, etc.
Completely rebuilt Continental engines are also available for $3000 or less as I found recently on the internet, but darned if I can recall where I saw it. A Google search would probably give a lot of leads.
Good luck, and feel free to drop me a note if you like.
Jerry Weiland
gjwslw@ameritech.net