There are two Saginaw steering boxes, the 800 and 808. One is slightly bigger than the other, don't remember which is which. The YJ and the XJ are the same, the smaller box, and some other vehicles (probably like the Durango) are the bigger box. AGR and the other places that sell and rebuild boxes sell both versions. Some folks have very good experience with a well built high performance pump and the bigger box. Most places recommend using the smaller box with hydro assist steering because it will be a little quicker and you don't need the extra power from the bigger box. Every place that sells performance built/rebuilt boxes sells them with and without the ports for assist, in case you want to leave that option open for later.
One of the things that wears out on a steering box when wheeled regularly with bigger tires is the bushing around the sector shaft. One of the basic upgrades on a performance built box is replacing that bushing with a bearing. You won't get the bearing in any stock box. Also, the clearances are checked in the performance box, and each company has it's own modifications that are done for performance and durability.
One of the hard things to work through when getting word of mouth on various PS steering companies is that nothing is absolutely perfect, it's always possible to get a bad product now and then, so it's important to hear how they stand behind their product. I use Tommy Lee, Lee Mfg, and have never had a problem. Tons of people use PSC and they have great products, and when there is the occasional problem they really stand behind the product and get it resolved. I know plenty of people who have had great success with AGR, and I've heard of some problems.
One of the issues when hearing about PS problems, and problems with product, is that many times a worn our component (box or especially pump) contaminates the system and that contamination takes out the new product, which the company gets blamed for. We've come to accept that in cases where there are ongoing problems, all components need to be changed to eliminate the contamination.
