JK_Dave
Caught the Bug
Any particular reason you're looking at that kit? Mopar uses Teraflex springs.
Just to put you in the right ball park without spending more money than you have to: to correctly run 4" of lift on a JKU you'll need springs, extended shocks appropriate for a 4" lift, extended brake lines, new sway bar links for the front (you can relocate the stock front links to the rear), front lower adjustable control arms to reset your caster and a new front drive shaft. You can put off the d/s for a later day, but if you go wheeling without it and use the lift to it's full potential, you will likely damage your stock shaft boot and/or joint.
Best of luck!
