my 1991 ranger xlt 4.0 6cyl 4x4 was just aligned at Firestone and they told me the caster and camber cannot be adjusted. I found that hard to believe because I am pretty sure the alignment bushings can correct this problem if I get the correct angle on the upper ball joint. Is it possible to look at what the values are and see what angle bushing I should put on the truck? Thanks for any advice you can provide.

Trying to attach photo of alignment results

Camber
left front: 0.8
Right front: 0.3

caster
left front: 0.2
right front: -0.4