Manual steering box worn out or can be adjusted?

Not sure how much you trust the guy that does your alignment, but before I laid out cash for a new steering box I would check to make sure that the play isn't somewhere else in the system. The steering coupler would be a good thing to rule out, as would the pitman and other steering components. Steering box bolts have also been known to loosen up, and steering box mounts on the K have certainly cracked, both of which can allow the entire box to move to move around. All things worth ruling out before you just replace the steering box.