Yes there were different length clutch fork balls but that was to use the clutch in a heavier truck with a bigger diameter clutch disc (14 inch instead of 11 for a high horse motor). To solve your non-stock pressure plate issue you need an after market solution. I recommend a McCleod adjustable clutch fork ball.
There were also three different height throw out bearings when you include trucks.
All GM cars used a diaphragm pressure plate, the Long or Borg and Beck three finger lever pressure plate holds better in high horsepower applications, but they are harder to use on the street why GM went with the diaphragm pressure plate and Ford and Chrysler used the three finger style.