Any tips with installing new steering box?

[chevymotocross]

I have an 87 swb 2wd. I've already jacked up the front and checked common things like tie rods, balljoints, idler arm, pitman arm, and wheel bearing play. The truck wanders unsafely at highway speeds. Not an alignment issue, it's an issue of a "light" feeling and just a bit of play, in the box itself. Everything else in the front end of the truck is solid. The wheel bearings do have some play, but isn't there suppose to be some play anyways? It's an even amount on both sides, but there is slight movement. Anyways, I got a remanufactured box for free from a buddy of mine who bought it at pepboys years ago and lost the receipt. It seems pretty straight-forward. I know I will need to rent a pitman puller. Is it hard to break the steering hoses lose? How do I know if the box is centered? Any other things to look at regarding the horrible wandering and loose feeling at highway speeds? I know I can adjust the box I have, but since I have a new one, I will just install it.

[chevymotocross]

I'm actually going to hold off on the box install. I work at a Town Fair Tire shop. I'm just a tire changer but I have become good friends with the alignment tech. He took a look at my truck and said the box is fine, I shouldn't even bother replacing it. He noticed, just by looking at it from a distance, that the caster is off, between right and left. If we put a hand, from the back of my tire, to the fender, there is more space on the drivers side, compared to the passenger side. That explains my pulling to the right problem. He said shims are used to adjust this. I guess we don't have these shims in stock, at Town Fair Tire, so I will have to wait. He said since the castor is off, it's obviously making the truck pull to the right, but it can also give me that uneasy feeling at highway speeds. Does this sound correct? I'm going to have him do a complete alignment, once the shims come in, before doing a steering box replacement.