CRC's Bronze Pivot Balls for the Pro-Strut Front End's lower arm are just about "bomb proof". The slightly larger OD fits the lower arm better than the delrin balls, even without the clamp screw installed. Plus, as the arm wears and you need to adjust the clamp screw, it doesn't squeeze the balls and pinch the king pin because the bronze material is much stronger than the delrin. The precision machined hole in the ball is perfect for the CRC king pins as well."