I have put K&N, mass air meter, underdrive pulleys, X pipes, aft cat systems etc on mine but all those $$$'s added together do not add up to what the 4:10 gears did. It is big dollar labor (gears are cheap) but the gears are still the best deal.
Put a larger throttle body on the intake and get your self an adjustable fuel regulator and restrict the fuel flow allitleI know this sounds counter procuctive but when you restrict fuel flow the fuel pump will then pump harder creating higher fuel pressure.