i have a 3" body lift in my truck right now and im buying a 6" suspention lift would i be able to keep my 3" lift on and have the 6" on to?

 

why wouldnt you, unless your state or where ever you live has limits, like in wisconsin where im from there is a limit and how high over stock you can go, but other than that there should be no problems at all, a body lift has nothing to do with a suspension lift, they dont interact with each other at all really.