I think you have the tie rod end in backwards. The inner and outer tie rod ends are different. The stud length is longer on the outer end if memory serves. I just did this on my '71 Challenger and put them in backwards myself. Pull the rod end-sleeve assy out and swap end for end.
I suspect if you look closely, the present inner tie rod end castelated nut is way down on the stud and the cotter key is not closely engaged either.