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!

[JHickson6]

?ttt

[Brad]

Okay, let me see here...I have a 77 unit on my 67. Also, I've got a 6 cyl pump; the tubes come out of it a little different. It's about 3 turns lock to lock, but mine may be the exception, based on what I've read about others. As far as mounting the gearbox, my frame has raised areas where it bolts to. However, based on my readings, seems like early 67 frames had no raised areas. Also, I still had to use 3 washers on each hole to clear the frame, even with the raised areas. I recall someone saying about .180 thousands more for this. My geometry changed slightly, but turning right or left, it's the same speed for me. Now, Wes or Pickmup has some insight on how the geometry changed on there ride-seems one of them has an issue of the truck turning quicker one way or the other. Bottom line is, you can do this, you've just got to space it out a tad and then have it aligned.

[rustedchevy]

lock to lock turns depends on steering wheel diameter also

ratio not changed, the two differences were variable or non variable thats affected by engine rpm

[70 Jimmy]

Sorry rusted chevy. That's a common misconception. "Lock to lock turns" is based on a 360 deg circle =1 turn. A steering wheel that is 13" in diameter has the same 360 degrees in a "turn" that a 17" one. A circle is a circle. A larger wheel will give you more leverage (easier turning) but require you to move your hand a longer distance due to the bigger curcumfirance [Spelling?] (slower turning). A smaller wheel will give you a similar effect as a tighter ratio box will, but you pump, or you will have to work harder. Hope this helps. Not trying to be rude

[rustedchevy]

well i meant that different size wheel affects ratio,
just didnt say it right, you did better job of explaining is all, no one had a misconception, smaller wheel wil make turn more with less wheel turn travel, ratio change

good luck