[rustyrims]

new poster here but I have been a mechanic all my life and I am over 70 years old. The most common reason for a bolt to fail like yours is it was over tightened. This is especially true on suspensions parts many give it a little extra. Before you redesign and sped lots of money just put it together carefully making sure the torque is right and it does not bottom in the threads. It is my understanding that these were modified by drilling and retapping which would be another reason it might have been over torqued. respectfully