[Jim A]

We finally found a sweet spot yesterday where the two necessary settings exist. It is a small one and perhaps fragile, but works.
Even though I have owned this truck for over fifty years and have never had anyone work on any part of it, I have a feeling that the interior clutch linkage is not stock.
As it is, the upper control rod runs out of threads long before it pushes the master piston half way in or less. I have a 1" extension on the end (inside the piston) that barely gives enough movement.
What would be helpful is if any of you have the opportunity to look at the geometry
of the clutch pedal arm and the control rod arm. Mine seem almost parallel. This means the rod starts movement forward too far back to reach the master cylinder.
If it is supposed to be maybe 30 degrees or more advanced of the pedal arm. it might work better.
The clamp system for the right end ( the control rod end) is not worn and clamps tightly. The other end of the connecting shaft (pedal end) has a weird fresh looking welded blob making the position. Fresh looking as in fifty years!
This is convoluted post, but if makes sense, please let me know your ideas.