What Joe is saying is that the pitman arm will only fit on a certain way. They are keyed to the shaft. Having said that, they can be installed either 90 or 180 degrees out, as the keyed slots are generaly placed at 90 degree intervals on a GM pitman arm. Now after reading some of the posts on the subject, it seems to me that when it was aligned, the mechanic did not take into account that the column had been disturbed and tried to set it for "strait ahead" to level the steering wheel. This is common, especially in shops that want high turnaruond on jobs, get the wheel strait and get it out. Joe's procedure would be the best way to get things centered.
