I've noticed it for a while now, but it seems to be more exaggerated with the 19.5s back on. When driving down the road, the truck wants to pull to whichever direction the road is crowned and I've got to counter steer a bit to go straight. Seems to me like it may be loose steering somewhere. Ball joints are good, tie rod ends look good, tires are wearing perfectly, everything seems to check out. Should I adjust the steering box? I figured I'd check here for opinions before I go messing with it. Thanks!

 

Steering boxes aren't that adjustable. Look at getting a steering box stabilizer.

 

I have found that the tires will cause what you are experiencing and not the steering system.

 

Make sure your trac bar is not wore or the bolt may be a little loose on the drivers side. Look for rust marks or cleaned spot where the trac bar mounts on either end. That would be the first place I'd look. Check it out, see what you may find. To counter steer on good crowned roads is not abnormal. Just the same check the front end out. I wouldn't touch the steering box, that is the last resort. Have someone in the truck and have them turn the wheel a little in each direction, pay attention to the sector shaft coming out of the bottom of the steering box. Make sure the shaft doesn't move side to side at all! then check the trac bar on either end. Make sure there's no play in that either. Check the tie rod ends too.