As a general rule if you just put rears in the front without any springs added to the packs you will only gain about 1" of lift. The added lift that people get is from adding arched springs to the pack from the rear to gain lift. And yes as Brandon said crossover is pretty much mandatory, I got away with out it but i had to limit my droop due to a shortened draglink. With the crossover setup I have now I have no need to limit anything but uptravel.
