Massive caster variance Side to side

The drive with caster this high didn't seem to be unusual. The steering wheel returns to center all by itself...when I let go of the wheel in a turn, it spins back to center. It didn't return with such intensity before when it had 3 degrees. Otherwise, It steered and drove fine. NO squeaks from the poly bushings in the UCAs but then...I used lots of chassis grease when I installed them.
I'm learning how some cars may look like others but sometimes a frame rail is slightly forward or behind another, the UCA mounts could be a fraction of an inch forward or back compared to the other side. Small variations will affect alignment.
To get the numbers I got, I did have to shim the lower ball joint on the right side. Otherwise, with the high caster, I couldn't get the camber to where I wanted. This is no different than the other little tuning tweaks we do to get our ignition curves just right, degreeing a camshaft, carburetor jets or air bleeds, it is just tuning instead of assembling.