are you sure the free play isnīt in the link from the steering wheel to the box... are you looking at the input splines when you move the wheel and the drag link? or are you just moving the wheel and watching the tires?
I havenīt measured how much free play there is normal, but I would suggest you look at the (lack of english word) near the steering box there is a cross thingy, I would think if there is possible to have free play somewhere it would be there. and there is also a croos inside the cab, inside the steering column.
good luck
What I do is too reach in under the hood and grab the steering column near the staring box and twist it back and forth(its that easy to twist the column within the free play) so I can see what's really happening with the pitman arm and there is no movement. The whole thing is mechanical connected right, so how can this be?
I'm also thinking of removing the steering box from the car and take it apart just to see if I can adjust it better then.
Thanks for the comments so far.