Steve is right on the mark, timing is subject to change from city to city and fuel station to fuel station. His way of setting the timing by way of driving, is going to be the best for your truck. All modern cars use computers to hold the timing right below the "ping" point at all times. They do it with a knock sensors, your knock sensor is your ears. If it pings under a decent load up a hill, but goes away if you give it full throttle, you are really close.
Dwell, timing, and fuel mixture are all related and need to be tweaked for optimal performance.
Joe
