Dodge: 318 tuning, spark plug wires, gas mileage

Question
I'd like to tune for optimum gas mileage. Can you give me some basic tips on what should be replaced that I can do myself at home with basic tools, also what gapping should I be going for on new plugs?  It has been about two years since it was last tuned up and I didn't do it. I don't even know what a decent tuneup consists of these days. This durango is a 99 with 104K on it's 318.Thanks,Terry

Answer
Change the spark plugs,distributor cap,rotor button,spark plug wires.This is a basic tune up.About all you can do to one for a tune up.Ask the person you buy the plugs from what the gap is,most of the plugs come pre gapped you just need to double check them before installing.