camber is always done with shims between the upper control arm shaft and the frame mounting point. You can't put them on the back side like they say. $90 is a decent price for doing it right. You need to set all 3, toe, caster, and camber. Gen1 can adjust caster, gen2 can't. Caster is adjusted on the gen1 by turning the upper CA shaft in the threads in the bushings for it. This tilts the steering pivot axis back and forth, changing the caster angle. More neg caster increases self centering and straight ahead cruising centering, while slightly increasing effort to turn. With larger tires, you want to add neg caster a tad above max factory spec. This really cuts down on wander. You also with big shoes want as close to zero camber as you can get. The truck sits stock with the bottoms in. Flatter is better with wider tires, for a larger all around contact patch that's equally loaded side to side. Factory toe seems to work fine, but go to an alignment shop with a side force gauge, as fine tuning the toe in with it is beneficial to tire wear.

Hopefully, you want a four wheel alignment. They can't adjust the rears, but it will align the front to the rear thrust line, and everybody will be happier. This is sometimes called a thrust angle alignment, and should be cheaper than a full 4 wheel alignment.

If you have a v6, make sure the trailing arm bushings on the rear axle are tight. On a 4cyl, make sure the spring and shackle bushings are tight...