I converted my truck to rack and pinion just behind the straight axle. Have not tested it yet, but it seems like a good idea. It resolves the old ball joints and should take all the play out. You should be able to do it even with the leaf springs in place. Of course I don't know what type of truck you have, but it may be the simplest solution. I have some info and pics at:
Pics of Steering upgrade Sorry for butting in, but I am just excited to see so many people that like to fix old trucks.
