Larry,
There is a bearing adjustment on the bottom end of the box but I doubt that is going to solve the problem. If the tie rods and the other components are tight and it has that much play, there is something wrong in the box. It's entirely possible that it was rebuilt with a questionable part that has now failed.
Fred


1956 3100 Pickup/Red/350/3sp OD/PS/Disc Brakes
1957 Bel Air Sport Coupe/Red/355/TH350/PS/Disc Brakes
2017 Silverado LT Single Cab SB/Black/5.3/6 Speed Trans
1947 Willys CJ2A w/F-Head engine