Also the shop manual is great to have, looks like one is included with the truck.
A cardboard box makes a great creeper if you need one, pick one up along the way.
For parts I get stuff from NAPA, for on the road repairs they have most all the stuff you'll need. You want to make your list and shop for spares before you start because some things might take a day or two to get in.
The biggest thing is trust that the truck can make it, do all you can to ensure it will, then hop in and drive. So many people are afraid to drive their old trucks very far from home, and that's foolish, how many miles do they rack up around town without trouble, think how far those miles would string out if you started driving and kept it pointed one way! They were all new once, and without hesitation were driven wherever they needed to go, no reason with a little care now they won't do it again.
A few years ago I made about an 8,000 mile around the country trip in my 52 1 ton, mechanically sound but nothing pretty. With exceptions of a generator bearing and a fan blade we had a great time, and even those problems didn't take more than a few hours to resolve.
Grigg