I found another post with the exact same issue and solved the same, with an acorn nut and some all thread. They used a steel acorn nut and grease. They also talked JB weld to plug the hole but I didn't see if they actually tried it. I found that brass acorn nuts wear too fast. I was constantly adjusting the clutch. Last week my throwout bearing puked ball bearings and froze from being out of adjustment so frequently (of course while my wife was driving). I get to tear it apart and fix it the right way now, and get a new pressure plate etc.
https://www.bangshift.com/forum/forum/bangshift/tech-section/1119778-clutch-fork-repair-84-c10
https://www.bangshift.com/forum/forum/bangshift/tech-section/1119778-clutch-fork-repair-84-c10