[Christ]

Diesel's don't overrev on factory settings because they literally run out of fuel.

If you have a Bosch pump, you can get more fueling through the RPM range by shimming the thickest of the springs on the governor shaft inside the pump. You can get more fuel advance (generally) by adding an inline fuel pump, which may make a little more power for you as well.

If your gearing is wrong, you could go up a tire size or two, but you won't gain much. Consider your differential gears. Many junkyards sell complete rear ends for around $75 or so, and they're VERY easy to swap between vehicles.