well right now i have just a 4inch lift with 35's ive been looking at the 12inch superlift with a 3inch body lift and putting 42's.. what else would i need with this kit besides longer brake lines? it says to lengthen the driveshafts and im not sure what that means but cant i buy the kit to lower the tcase? any help would be appreciated

heres the link to the lift

http://www.ntwonline.com/73-87_GM_1_...P12587C826.cfm