[Trailduster79]

I am looking to overdrive my power steering pump.  Truck doesn't see high RPM's, mainly trail riding/rock crawling.  Would like to get some more flow out of the pump at idle and just off idle for my hydraulic assist.

I have already done the mods to make the pump flow more and with more pressure.

79 Trailduster, 360, stock pump.

 

[Rabbit929]

A person could measure the shaft diameter and sheave diameter, then find a similar one but smaller OD?
many of these pumps are similar between makes and models, but a small car might have a smaller sheave.

 

[KurtfromLaQuinta]

Mopar Action Magazine (Rick Ehrenberg- their tech guy) did and article on general steering differences... https://www.allpar.com/history/mopar/steeroids.html
I don't know if this will help you. But there are links to other sources at the bottom of the article that might steer you in right direction.
I know he did and article specifically on Saginaw pumps a while back. I didn't find it. You my be able to dig deeper than I did. Try here... https://www.allpar.com/history/mopar/index.html