Power Steering Gearboxes

[JHickson6]

I have a 67 chassis right now that had power steering from the factory. I have heard on here before that the 73-up gearboxes are quicker ratio. My questions are how much better are they? Does anyone know the ratio differences or how it reflects on the number of turns of the steering wheel from lock to lock? How about the mounting on the frame, should I expect any problems? (Dumb question, there's always problems) Or do i just need spacers on the bolts? Will this throw off any of the steering geometry because the gearbox would be slightly further to the driverside than the original gearbox?
Thanks guys, any help would be appreciated!