Well the short list of issues I would suspect before the frame, A Arm bushing or arms bent them selfs, Arm thru bolt, Ball joints, Outer tie rods,
Rack. I would expect any one of these items to be suspect before the frame.
When the steering wheel is straight, what do the tires look like viewed from the front? This may give a good clue.
I would agree with others, find a better shop.
Is this guy in Wasilla, Palmer or Anchorage or one of the other areas around? I would expect some good alignment shops in Anchorage, Eagle river, Wasilla areas over Palmer(but who knows, since Palmer has been around longer than either Anchorage and Wasilla).
Personally I would find a real good Alignment shop, because at the end of the day, the truck will need an alignment after the issue is found and repaired.
May want to get the work done in one place.
Hope you buddy get it done right.