better MPG

With a truck it'll be tough to get noticeable improvements in gas mileage. What rumblefish recommended is good, along with a properly set advance curve. More advance will give you more power AND mileage (improves overall efficiency of the engine), but to an extent, of course. Set initial around 10-12* advanced with about 34* total around 2600 RPM. Also make sure you're running as much vacuum advance as possible without running into ping at cruising speeds.