2.5" spacer and 3" body lift will give you about 6". Otherwise, combining a 1500 kit with some custom springs might work. I would have to take a look to see if the 2500 knucks are the same as the 1500 knuckles.
You can do that as well, I can give you alot of input on if you want to do a custom setup. If the knuckles are the same, you could start out with a CST 4" lift spindle, that would get you up in the air quick, then add a spacer and you would get 6" in a hurry.
A forum community dedicated to Dodge Cummins Diesel truck owners and enthusiasts. Come join the discussion about reviews, drivetrain swaps, turbos, modifications, classifieds, builds, troubleshooting, maintenance, and more!