[ursus]

Also, there is a very important spring-loaded camshaft thrust tensioner at the front end of the engine. The spring inside of the plunger can get rusty and break, especially in engines that have been sitting around for a long time. This allows the camshaft to walk back and forth with highly variable ignition timing. I found a car like yours and experienced the same set of symptoms - I could carefully time the engine but it would soon spit and sputter so badly I could not drive it. Check this out when you get the timing cover off!