The attached is a depiction of what has happened. The LCA's were part of a kit I bought from California Mustang back in the 80's. Maybe they were just crap control arms and the press fit of the bushing-to-Control Arm was not tight enough? One of my rancheros has a similar situation, but not as bad as the mustang. The movement of the LCA vs the bushings happened gradually.
In the attachment, I simulated the bushing being off center. The gray pieces represent the frame support for the inner pivot of the LCA.
@Cleveland Crush: A few months back, I measured -2.2 deg on the left and -1 on the right. Toe and camber were in spec. My turn plates didn't have angle pointers, so the values probably have some error. Since then, I added pointers to the plates.
I'm planning to target 3 degrees of caster. To achieve that, will require a shim behind the forward bolt of the UCA. Previously, I posted with the characterization table and graph, for anyone interested. The table and graph was a result of a kinematic CAD model I created to characterize the suspension's behavior. The focus was on shim thickness vs caster angle.
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