I think Bob is right. I have never been a fan of rack and pinion steering on an I beam or tube axle set up. To work right, they have to move with the axle, and therefore be mounted to it, like the one you described you saw. But they become unsprung weight, and it is hard to get the steering column shaft to move with the axle movement.

I also think they look somewhat ugly on there, but that is just my personal opinion.

Don