eyeball method

I like lots of caster, i like my cars to steer like a road grader or dragster. An easy way to tell you have "enough" is to note that wheel on the outward side of the turn is facing the sky and the inboard wheel (left side if turned to the left) is facing the ground. You can't easily sight from top to bottom ball joint unless the brakes are of. With brakes and backing plates off it's easy.