PS, that camber tool, and a tape measure, is all a good shadetree mechanic needs to get their alignment passable.
Use that gauge to check camber, and a tape measure to measure toe, boom, done. You use the tape measure from the front of the left and right rims, compare with a reading from the rear of the rims, you can at least see if your wheels are parallel. It won't show if they are centered compared to steering wheel position, or if they are trackign the same track as the rear wheels, but will at least let you know what your toe in and out is. Then adjust tie rod ends to correct, done.
My father in law, 25+ year experienced alignment man, uses that method, and has yet to have a computerized alignment system prove him wrong, no matter how many times I challenge him on it.
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