As said previously
1, RV TQ Cam
2, Bigger Injectors
3, Higher Stall Torque Converter
4, A Computer reprogram by a Good Dyno Tune Shop,
If you can do 1-3, you may do it for less than $2,500, extras included. And you'll lose MPG,
Had a '05-2500, 4.8 for 179,000+miles, sometimes pulled heavy...