Date registered: Aug 2008
Vehicle: 1971 250C
Location: Toronto, Canada
Mentioned: 0 Post(s)
Quoted: 14 Post(s)
That would be your expertise; I'm not that good at artistic stuff as you.
It sounds you have done more extensive troubleshooting that most of us would do.
I'm very doubtfull that warped head on the manifold side can cause what you are describing but I am not rulling out either. It must significant warpage, visual to the eye to do something what you are describing.
Have you looked at the timing chain? Few members have had timing chain worn to a level that would offset the engine timing.
Just a thought.