Door striker posts.

It's not enough to just weld up the area. You need to add a layer of reinforcement metal to the back side. Before '71 or '72 the factory didn't do it. In later years they did (you'll find a reinforcement plate in there). The cage for the captive nut needs to be removed first and then a layer added. Of course, you want to make sure your door hinges aren't worn out too.