How does Caster play with Camber

[exwestracer]

Referring to your description of a typical cross shaft upper A arm with shims; the difference in shim stacks will angle the A arm either to the front or rear of the car. This moves the upper ball joint ahead or behind relative to the lower ball joint. The angle of a line between the ball joints in side view is caster. More shims in front would result in LESS caster angle, as the upper ball joint is further forward.

Camber gain is affected more by the height of the upper A arm mounts in relation to the lower ball joint.