Joe, that's a 2-speed differential. An underdrive. How many cylinders does the engine have? You'll want to put a few miles on the old girl to familiarize yourself with her peccadilloes - she'll have some - and to be sure she's up to par for a long drive. Unless she has been extensively updated, she'll be slower than you think. That ain't a bad thing, you just have to get used to it. Pay particular attention to tire pressures and load security. And everything else, come to think of it.
It has been some time since I was down that far, but take a look at a map and consider Hwy.#US97 north of Weed, CA, then #OR58 into Eugene, OR. It's flatter, therefore easier on the old stuff, and quicker and less crazy than I-5. And there's a nice hot spring near Oakridge, OR so you could take a dip to ease the sore muscles you WILL have.
