Can someone explain the clutch ajustment as it pertains to the fork free play? Not sure what that means

Basically you do not want the fork pressing against the throw out bearing when the clutch pedal is released. You should have about 1 to 1.5 inched of travel (at the pedal) as you push the pedal down before the fork touches the throw out bearing. As the clutch wears the throw out bearing moves closer to the fork and you will have to add free play. a fork that touches the throw out bearing all the time will #1 cause the throw out bearing to rotate all the time which wears it out and #2 can cause the clutch to slip. I hope that makes sense

The fork needs to pull back the throwout bearing from the pressure plate slightly such as 0.1-0.125". However to do this properly you should remove the inspection plate down below as adjusting the free play up top does not account for wear/tear of the clutch linkage after 40 years..

Just my $0.02...

The factory says to adjust the pushrod gap at the throwout fork at 5/32".

I've concluded that adjustment is not the issue. I either have a bad throwout bearing, pilot bushing or both. I'm also not rulling out that the bell housing is misaligned.

When you push in and let the clutch out it makes a grinding sound. Had it up on the rack today and with it running it didn't make the sound until we tried to keep the rear tirs from spinning.