[metroschultz]

You can change the cam timing, without changing the cam itself for a boost in economy. There are cam gear kits available for virtually every car made. (I got a +10* gear from 3tech.com)
Advance the cam timing by 10* and this will effectively lower the RPM of the power band. Allowing you to use less pedal for more torque.

Much of your fuel is used to move your truck from standing to rolling. By lowering the torque curve, you make it easier for the motor to move the truck and use less fuel to get there.

You will also lower your peak RPM. This means no more rolling thunder at 90MPH on the highway.

You will notice your truck pulls easier but doesn't have as much a$$ in the top speed area.

I don't roll past 60MPH anyway, so I didn't see any problem with my +10* cam gear.
Hope this helps.