My van is a 1990 GMC Vandura 2500. It has a 5.7L (350) FUEL INJECTED V8. The caps are for the noobs out there that need to be schooled: electronic fuel injection or bust if you get a van.
I won't go into too much detail on the how, but the why is definitely a must. First, electricity is not the necessity we sometimes make it out to be. In order for you to have a good electrical setup that doesn't require a lot of driving to charge your batteries, you need to spend about 1,000 dollars...at least. I'd suggest you get off that idea. Right now my van meets all my needs, including food storage and preparation. Wal-Mart has all the toilet you need in a convenient 24 hour package, but I frequently suffer from diarrhea, so I'm getting a toilet in there too.
1. Sleeping: Just a twin mattress, but I suggest you build your own bedframe as I did. the 16 inches of vertical storage space underneath it is invaluable.
2. Food: Coleman camp stove/grill. The grill comes in handy when you don't want to clean a pan. It traps the grease. Don't cook heavily seasoned meat in your van though. It smells for days. Chicken leaves the least odor, unless you're a garlic fiend. These stoves claim to run 1.1 hour with both the grill and stove on high off of one 16.4 oz propane canister. You will never need to turn both on high or either on high individually, as this thing gets HOT! This translates into you getting about 10 meals out of 1 canister. Easy. Also, unless you want to die in a fire or of carbon monoxide poisoning, I suggest you get an ABC fire extinguisher and either a vent or cook with both front windows open and your curtain drawn. I've found also that just about any 5 day cooler (mine is a 60 US quart Igloo cooler) will keep your food cold enough.
3. Hygiene: Babywipes and mouthwash. I have a sink in my van that I cut into a dresser with the drawers removed.
Also, check out the yahoo group VanDwellers2