Looking for a New steerng box

[Gray 5.9]

I'm having a problem keeping my truck straight goingdown the road. Hear lately I've had to counter steer alot when ever I : Go from uneven paved surfaces, hit pot holes, dips, and everything else . I've elimanated the track bar problem with a Lukes Link fix, New ball joints, Had the front end alligned by a shop that doe's big truck's and pickups, and they say that all the joints are tight and in good shape. They said when they took it for a test drive, that they noticed the gear box had some play it. I toled them that I've adjust the gear box three times before and each time I done it , it would drive good again. I talked to the Guy that did the allignment and he said the last few trucks worked on had the the same problem. This steering box is made by saganaw, the same thats in GM vehicles. I was told that the specs are different on Dodges than on other Saganaw applications. If I can, I'd like to get the best gear box and pump that I can get...This trucks been real good to me. Getting the bugs out is the only thing standing between me and my truck......Thanks