Found my problem... I did end up getting the rear one to fit into the yoke with the clips so the caps wouldn't move...I also found the front u joint was "binding up" ever so slightly. When I installed it the front moved free and smooth but the caps must have not been seated all the way and after driving a short distance they moved...couple of light smacks to one of the caps and the opposite yoke ear and it was as smooth as butter again. Reinstalled the driveshaft and problem solved no more vibration.