Great suggestions, and thanks to one and all. For Hotrod, I can confirm that there was no 3-axis geometry applied to the power steering swap. I bought a kit from Chevy Duty and a PS pump and box from a junk yard, and followed the instructions.

I appreciate the description of the intersection of imaginary lines, and why wider tires lead to problems. I certainly don't want wider tires on the truck, because the ones I have already scrape the inside of the rear fender with any kind of load.

Please explain 'bump steer'.