I DO like the pig bus. Have you seen this one?
This is a pretty famous Bus; it's called Roadcow. The weird lump on the roof is because Roadcow has a Toyota engine in it, and they needed somewhere to put the radiator.
Back to the seriousness:
a) Shell Rotella T 30-weight is your friend. Volkswagen engines run far hotter than watercooled engines do, BY DESIGN, so you want an oil made for hot-running engines. The hottest-running engine is an old two-stroke Detroit Diesel, so use the oil recommended in the Detroit Diesel manual--which is 30-weight Rotella. Don't bother going to a truck stop to get this (partly because truck stop oil is overpriced and partly because truck stops only carry 15W40 Rotella); NAPA has it.
b) Speaking of oil, your engine holds 2500cc of oil. You can get all the litres of oil you want in Germany, where your Bus was made. You are probably not in Germany, and here you get oil in quarts. Put two and a half quarts of oil in your engine and be done with it. You'll read a little low on the stick, but if you read EVEN A SLIGHT BIT HIGH ON THE STICK YOU WILL BLOW THE OIL SEAL. Changing an oil seal on a VW is a huge pain in the ass.
c) Oil change interval on old Bugs and 71-earlier Buses is 1500 miles. This is not negotiable because your car has no oil filter. 72-on Buses DO have oil filters, so you can get 3000 miles out of them.
d) A Bus weighs 2700 pounds and it has 60 horsepower. Semis go up hills faster than you can. If you floorboard the Bus to attempt to get up the hill faster, you will do nothing but burn up your engine. No more than half throttle up a hill, please.
e) The most critical thing I am going to tell you: Look at your tires. Not the tread (well, look at that too) but the writing on the sidewalls. If you do not see REINFORCED SIDEWALL, LOAD RANGE C or LOAD RANGE D on your tires, get rid of 'em and put some truck tires on. If you are seriously flush with cash, get Michelin Agilis; busdepot.com has some Hankook tires that are very good. Running car tires on a Bus will kill you; they can't deal with the load the car puts on them and the sidewalls fail.
f) A properly timed engine is a cool-running engine. If you've got a 72-on Bus the timing procedure is different because the engine's different, but on a Bug or a 71-earlier Bus, you set the valves, hook up your timing light and set the timing to 5 degrees before TDC--if you're running the original crank pulley there's a notch filed in the rim; set the timing so that notch is aligned with the crack in the case. And after that's done, before you tighten the distributor clamp take the hand that doesn't have the distributor in it, reach over to the throttle arm and yank the arm back toward you. If the engine slows down before it speeds up, turn the distributor just a little tiny bit (maybe a tenth of a degree, or less) and try it again. If it doesn't slow down at all, tighten the distributor clamp. If it slows down still but less than before, turn the distributor just a little bit more and try it again. If it gets worse, go the other way.
g) A sheet of plywood will go through the back door (the one above the engine compartment lid). If only two people are going on this trip you can make a great bed platform by purchasing a sheet of 3/4" plywood and a 2x4.