Stuart,
That is the clutch fork pivot ball. It is screwed into the inside of the clutch housing.
"shift linkage bellcrank"
I think that Craig/49 Panel is referring to the pivot for the shift linkage that is on the outside of the clutch housing on the driver's side. The 3-speed linkage rods attach to brackets that pivot on that "pin". This pivot pin is not needed on a 4-speed. Of course, as is usual, I could easily be wrong.
Tim
