you can buy suspension software that helps you correctly setup a triangulated suspension, specific to your jeep. an incorrect setup can cause all sorts of bad things, suspension to soft/hard, incorrect steering angles, screwed up center of gravity, binding, pinion angles can't be set, etc. im no engineer so i don't know the specifics of it all, but i know its better to have a proper functioning leaf spring setup, than a bad 4 link setup. do ALOT of research.