1970 A833 issue jumping out of 2nd gear

Pretty much the same problem with my Dart, same transmission and year. Did a tear down for inspection and found nothing worn replaced the seals and gaskets regardless. Used a drill blank in the shifter fork hole to adjust the shifter linkage, just did not feel right. I had to manually move the 1st and 2nd transmission lever on the trans and then bring my linkage up to the lever and adjust to find the sweet spot for the arm to slid in centered in the lever hole. After adjusting it this way, the transmission shifted nicely, but again the drill blank would not fit into the alignment hole. Go figure.