With my old girl, I could not get a good alignment no matter the 4 shops I tried- so I wound up doing it myself. Used 4each 8x8 blocks about 18" long, 2 ea. 3/4x1 1/2 25 ft long.(had these), and another 3/4x 1 1/2 about 7 feet. Put the blocks next to tires, set long tubes on top and push against tires. May need to use some 3 foot tubes as shims front or back for wheel track spacing.Now that tires straight, measure distance from rim to rim each side. They better be equal. Now you can easily see/measure toe, and see if there is a difference left or right. Next - buy a couple 2-3 wheel rim clamps, the kind that push in between tire and rim, and some aluminum angle 2x2x1/8 about 6 feet. Make a TEE that fits about the centerline of the wheel. Make sure i'ts square. Use 3 screws/nuts washers to secure angle. Attach wheel clamps to this then attach to wheel. Level it front/rear. Use your angle finder on this now. Shows Camber. Set to Vertical then turn wheel left(drivers side) about 30 degrees or so. check vertical angle (write it down)measure angle turned. Reset Vertical to zero. Turn wheel straight ahead.(write down angle) . A little math and you have Caster. Factory specs are about 3 1/2 degrees caster max. Lucky if you can get 1 1/2. which I consider MINIMUM. If your rim to rim distance is off more than about 1/16 truck will wander like crazy. If you cant get enough caster you may need delco 45k0824cam bolts2 1/4 degrees, and 45k0201offset control arm bushings 1 degree. Set toe to about 1/16. Anything more than this and mileage drops 2mpg, along with front tires wearing in 40000 miles not 75000. Set camber to zero. Hope this helps.