are these a wear item that need replacing?
GM parts
https://www.kijiji.ca/v-transmission-drive-train/london/1964-68-muncie-trans-shift-fork-levers/1432498153?enableSearchNavigationFlag=true
1966 Strato Chief 2 door, 427 4 speed, 45,000 original miles
1966 Grande Parisienne, 396 1 of 23 factory air cars (now converted to a "factory" 4 speed)