When I originally lifted mine about 10 years ago I got a 3" Rough Country lift that came with the cross member drop, dropped pitman arm, and brake line relocation brackets. I added 2" lift shackles, which add 1" of lift. The shackles made the shocks too short so I replaced them soon after. So...the moral of the story, a good 4" kit will have everything you need to be road worthy. Many will tell you that you MUST have a SYE and CV drive shaft with 4" of lift, but that is not always true. There are tons of guys out there running 4" with stock shafts. I had a little drive shaft vibration under hard acceleration, but in 10+ years never had to replace a universal.