I have a friend who just picked up a "used" 4" lift kit for his Jeep J10 (or JP10?). It is a set of Rancho front springs and factory rears with a block. Now I know I wouldn't personally have bought a used set-up but he did and I am going to help him install it on the rig. Yet, the kit didn't come with the shackles for the front spring. What shackles are required?