U-bolt installation on an 8 3/4 housing

They aren't aftermarket, they have the flat spot in the top of the U to distribute the pressure on the housing and each one is consistently 1/4 to 3/8 of an inch longer on one side. I wonder if the factory tightening procedure or the stresses on the housing over 40-50 years actually distorted the bolt so it's pulled one side down unevenly??? Wierd!