The only thing that works is to build the engine, Cam, Header, Exhaust, and then add a piggy back engine controller to the ECM. With the truck on a Dyno the fuel and ignition can be modified to take full advantage of the modifications.
The other mod that it has been reported can make a huge difference in a stock or modified engine is a MSD or Jacobs multi-spark ignition system. I don't have any definitive data but I think it is because the multi-spark more completely burns the fuel which tricks the O2 sensor into thinking the mixture is lean.