Tim, The hole in the door where that pin engages has NO threads. That post that is on the longest part of the frame, simply drops into a hole inside the door frame and is retained with a nut. That part of the window frame simply aligns the rear of the assembly. In fact, if you look at the pin where it goes through your frame assembly, it should have a piece of foam wrapped around it to keep it from vibrating. At the upper end of that leg , and just below and to the rear of the window opening, there is a pinch bracket, with a slot in it. That is what retains the vent assembly in the rear from up and down movement. There is a bolt in that area that gets tightened after the assembly is in place to achieve this. 68's are the same, I just did mine recently. @Mopar Tim
