Heres where you move that axle from below your leaf spring to sitting on top of your leaf spring for the express purpose of getting the maximum amount of drop! This is a lot of work so you're a serious enthusiast looking for a serious drop when you “flip axles”. On the 99 – 06 Chevy’s the frame is straight and when you flip you need to “C-section” the frame to get back some of the travel you lose because of the “flip”. Thats where the cutting and grinding comes in! DJM flip kits feature big thick frame reinforcements, axle brackets that allow you to set the pinion angle, a shock extender and a whole bunch of hardware.