Suspension & Brakes - Stock LCA axle mounts not even?

I installed some UMI weld in LCA lowering brackets, as a final check I measured from the front a-arm bolt to the rear lower control arm bolt. There is a 3/8" difference between the two sides. It's not the brackets either because I measured to the stock location and it's off by the same amount.
I guess I could have corrected this before welding the bracket on but I didn't measure it first.
The wheels in the wheel wells measures different from side to side too.

The brackets must be welded on wrong from the factory because the car hasn't been wrecked, it's got UMI LCA's too.
Is this a common problem?

I know the rear ends of f-bodys don't line up exactly. It takes an adjustable panhard bar to line the rear wheels with the fender of the car.

I know the rear ends of f-bodys don't line up exactly. It takes an adjustable panhard bar to line the rear wheels with the fender of the car.

How is that? The adjustable panhard bar would move the rear side to side.

My rear is more forward on one side.

How is that? The adjustable panhard bar would move the rear side to side.
My rear is more forward on one side.Well, in your original post you also mentioned that the wheels measure different side to side also. The panhard bar would allow you to correct this.
I believe that you would need a set of adjustable LCAs to correct the front to back issue.

my driver side wheel set a little further forward than my pass side wheel...

Well, in your original post you also mentioned that the wheels measure different side to side also. The panhard bar would allow you to correct this.
I believe that you would need a set of adjustable LCAs to correct the front to back issue.

The wheels in the wheel wells measures different from side to side too. Meaning from left side to right side they measure different. Left side is about 3/8" forward as compared to the right side.

If I may re-interpret, what you are saying is that the distance from the rear d/s wheel to the front d/s wheel is different from the rear p/s wheel to the front p/s wheel? Or some similar relationship, correct?
If so, that would be expected, since one would hope that the relationship between the LCAs and the axles to be one-to-one.
I would expect that adjustable LCAs would correct the issue.

If I may re-interpret, what you are saying is that the distance from the rear d/s wheel to the front d/s wheel is different from the rear p/s wheel to the front p/s wheel? Or some similar relationship, correct?
If so, that would be expected, since one would hope that the relationship between the LCAs and the axles to be one-to-one.
I would expect that adjustable LCAs would correct the issue.

Yes except I measured from a more common point on the front, since turning the front wheels might effect the measurement. I measured from the front lower a arm bolt c/l to the rear lower control arm bolt c/l. Everything installed and sitting on the wheels. The LCA lowering brackets are welded on and the LCA can be unbolted and moved to all three holes without moving the rear housing, plus the measurement to the stock LCA brackets is off also.
So do you know if this problem is common? it's different by about 3/8 of an inch.

No, I don't know if this is common or not. Since adjustable LCAs are common, I suspect that it is common. But that is only using logic, not experience.