I installed a pair of back leaf spring, a friend gave me, they looked better than the ones i had, so what the heck, they were free...set them side by side with the old ones the height and length were the same, but seamed heaver. Problem was i had to install the shocks with the boots down becouse the body of the shock was hitting the axle and could install top bolt. The jeep was on jacks so would this make a driffrece. Is this a problem, do i need shims ??