Install the new leaf spring: Be sure to orient the new leaf spring so that it points downward on each end. Align the small center stud on the backside of the leaf spring with the factory indentation on the bottom of the rearend. As you turn red in the face holding the spring, place the center mounting plate on the bottom side of the leaf spring and start each of the four bolts into the rearend. Once the bolts are started, the weight of the spring will be on the center mounting plate. So that the spring lifts evenly, tighten the bolts in a cross-alternating fashion until the bolts are all fully tight. As you tighten, be sure that the line-up stud aligns correctly with the rearend.