Did a bit more checking on the 77 Dodge 318 in my camper van. Compression is 135 to 150 over the range of 8 cylinders. Squirting oil in one of the 135 holes, pumps it up to 160. This van had been sitting for about ten years, and has around 55000 miles.
Vacuum is 18, pounds I assume, with a very minor flutter. Not even one quarter of a pound flutter, but the needle is not rock steady. Watching stuff on you tube, shows flutter at 2 or three, or more pounds of flutter. So I assume this is not bad. But I can hear a flutter when I rev the motor. Next on the list is to check the valves for opening and closing, and checking all the rubber lines/hoses for possible vacuum leaks.
I will be removing the radiator, alternator and power steering pump. That will give me access to the font of the engine, so I can turn the crank.
The engine pros are welcome for their input.
Herb 9N has about 112 pounds of pressure. Island Mike