Originally Posted by BrandonMski
You can change your gear ratio.
That might not work, see if he increases the axle ratio he will have better acceleration, but he may lower his top speed depending on the specifications of the rest of the drivetrain and might not get better mileage since the engine will be operating at a slightly higher speed. If he gets with a smaller axle ratio, he won't have as good an acceleration and may actually get worse mileage because the engine might lug especially in 4th gear. A 3.55:1 axle ratio is really the best of both worlds for these trucks.