Hello, I just bought a 2009 Duramax 6.6L turbodiesel. I'm still trying to figure out what it's all got installed. I have a Rough Country 6" lift with 325/60r20 tires. I know it's got an EFI 5 stage live tuner and an AirDog lift pump. I'm trying to figure out what are some good mods that won't hurt the engine in the long run. I don't have to be the fastest truck out there but I like some speed and power for off roading. I just invested $20k+ for the next six years, so I don't want to kill my engine or trans just to go fast. Any help would be great.