When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Stock stuff is one option, BUT IF you want to run more modern rubber you will find that steering designed primarily for trucks in the '50s is not the best for modern sports car rubber on the road....there is a reason modern cars use rack/pinion tech...or at the very least integral recirc/ball power boxes.....
many threads here in r/p installs, and Jeep box conversions....
Least expensive is stock used on Ebay or from a show or whatever. Good kit is from VBP (a nice forum sponsor). But I am going to agree with MrVette that if you are going to change it there are more modern options. I prefer the "Jeep" box over Steeroids.
I have a near-complete power steering system from my '80 I'll part with for a $100 plus shipping. (VB&P offer is $99.) There may be a bolt or nut missing, but nothing you can't pick up at a hardware store with a good selection of bolts. Everything was working well when I switched to Steeroids and replaced my power steering pump in the process, but the control valve was leaking a bit. Unopened rebuild kits for the cylinder and control valve are included, thus the $1 premium price.