67-9 2dr sedan door striker repair

My car is a 71 and had the same problem. With sagging doors and thin metal round the striker it's gonna happen. I had a 73 parts car and the jambs were perfect. They had about a 4" sq 1/4 backing plate. So I drilled out the striker and added it to the 71. Hope this gives you an idea. So parts car or a kit, it's your choice. Hope this helps.