How bad is that to change?
I personally would look into getting a remanufactured box, and swap it. You will need a pitman arm puller and a good impact to get the pitman arm off.
If you get a remanufactured box, you will have minimal downtime (with a core charge until you bring in your box).
Advanced Auto has a limited lifetime warranty (not sure what that means) box for just under $300 with a $160 core charge:
https://shop.advanceautoparts.com/p...ic-27-5203/10314477-P?searchTerm=steering+box
I've changed boxes before on a jeep:
1)Remove steering arm to pitman arm, then pitman arm
1a) Put pressure on the pitman arm with the puller, then tap the side of the pitman arm around the splines with a hammer. Then add more presser, and hammer again. Repeat this over and over until it pops off.
2) Remove hoses (drain all fluid that comes out) you can do this befer the pitman arm if you want
3) Swap boxes (when you pick up the reman box, you will realize how heavy these boxes are, so be very careful it doesn't fall on anything you care about). You will have to remove the steering column from the box. I am not sure there are clock springs on these trucks, but DONT TURN THE STEERING WHEEL WHILE YOU HAVE THE BOX REMOVED... VERY IMPORTANT OR YOU WILL HAVE TO REPLACE THIS BY REMOVING YOUR STEERING WHEEL...
4) Attach hoses, attach steering arm and pitman arm (Strong impact)
5) Bleed the system, jack up the vehicle, with the engine off and key in (unlock the steering column) turn from lock to lock 20-30 times while topping off the reservoir (pays to have a helper). Once the bubbling stops in the reservoir and the level is stable, you are good.