First-generation '65-'66 Mustang camber and caster adjustment takes place at the upper con
Alignment shops used to use a bubble gauge mounted on the wheel to adjust camber and caste
Camber can be tricky because it changes as you drive. This is why Ford provided a range of camber to play with. At rest, approximately 1/4-degree negative camber is good for tire wear. If handling is more important than tire wear, you can add negative camber at the sacrifice of tire life.
First-generation '65-'66 Mustang camber adjustment takes place at the upper control arm via shims at the two control-arm attachment points. Add shims to push the arm out toward positive camber and subtract them to allow the arm to move in toward negative camber.
From '67-'73, Ford revised the Mustang's front suspension for easier camber and caster adjustment. Instead of using shims on the upper control arms, Ford went to an adjustable lower control arm. Adjustment is facilitated via an eccentric on each lower control-arm fulcrum. Roll the eccentric to move the arm in or out to change camber.
From '74-'78, the Mustang's front suspension system changed completely to rack-and-pinion steering, with coils and shocks located between the upper and lower control arms. This makes the Mustang II's front suspension more like the '67-'81 Chevrolet Camaro and Pontiac Firebird. The upper control arm on the Mustang II is adjustable, much the same way as its GM counterparts. The upper arm moves in and out to change camber.
In '79, Ford greatly simplified the Mustang's front-end alignment process by eliminating the upper control arm and going with fully adjustable MacPherson struts. To change camber, the strut is moved in and out. The same can be said for '05-'07 Mustangs, which also have MacPherson struts.
What Is Caster?
Caster is spindle angle from top to bottom, or the positioning of the upper and lower ball joints as they relate to one another. If the spindle is tipped forward, it creates negative caster. If tipped aft, it creates positive caster. This controls spindle geometry as the car turns. Think of caster as how the tire/wheel articulates around the axis that connects both ball joints.