Jim Carters is now selling replacement steering shafts and ball nuts. He had one at a show I was today. Might be expensive, but it would be brand new. If you can find another truck in the same age group, rob the parts from it. I used a 2 ton shaft for may 1/2 gear box by cutting a section out of the shaft to shorten back to the correct length. The boxes were all the same, the shaft length is what they changed.
Joe