cbattles,
You are correct that there is one adjustment that's pretty easy to make that can take some lash out of an older box with a lot of miles on it, but 1/4 turn is a LOT of adjustment for this bolt. Usually turning it just 1/16 or 1/8 turn is enough. If you go too much, you'll notice that the steering "sticks", and you have no return to center. You'll be "herding" the truck down the road constantly...
Buddha,
Glad you found the issue! That bolt should have had a factory locktite patch on it... Not sure what would have it coming loose...
Might want to say where you are, roughly... Someone here might be looking for a reman box and could take the rockauto unit off your hands. If that box was truly loose, you would notice that you can shake the pitman arm a bit. (Which means nobody probably wants it...) What was the steering feel like on the reman box anyway? I'm still wondering why the unit we put in our brush truck has absolutely no steering feel.