Hey Gary, it's a long shot but I found these notes in my files from when I had my p30 my parts guy was pretty good and I have noted two different lower ball joints for the p chassis. Moog K6122 and K6175 the first has a narrower shaft the second is the correct one. I know your front end was pretty much rebuilt. Wonder if they used the narrower shaft one. When hitting a bump would possibly make noise and while braking puts pressure on it and goes away? IDK just thinking out loud. If you happen to have a receipt with parts and numbers used. Hope you can figure out your problem.