To continue with the Captain's comments, I don't think there is a master spline on the pitman arm so as he stated, disconnect it with wheels pointed forward. Find lock to lock distance, split it in half or if you prefer a tighter right turn radius and reinstall the pitman arm with everything pointed forward at that point. After that, pull the steering wheel and center it to match. Instead of shimming to function the steering gear, I would take it to a frame shop and let them look at it. Should not be a big problem to straighten for someone that knows that kind of work.
