Installation instructions for rear parallel leaf spring kit for 1949-54 Pontiac

1) Locate and mark rear axle centerline on frame rails.

2) Measure 24” ahead of centerline and mark frame rails. Measure 23 ½” behind axle centerline and mark frame rails.

3) Locate center of front spring hanger bolt hole on front marks, angled part of bracket goes forward, with bracket side 1” out from frame rail side. Clamp bracket in place to bottom of frame.

4) Locate rear shackle hangers with the center of the shackle tube on the rear marks and the boxing plate on inside of frame rail. Clamp in place.

5) Install springs and shackles into hangers. Check to make sure center bolts of the springs are centered on the axle centerline. Double check all measurements and make sure springs are parallel with each other. If not adjust front bracket in or out until the springs are parallel and the brackets are the same distance out from the frame on both sides. When everything is right, tack weld brackets in place. Remove springs and weld in place.

6) Reinstall springs, set spring perches in place on centerbolts of springs. Set your axle housing in place on springs, centering it from side to side. Rotate pinion snout of axle until it is in the same plane up as the transmission is down. With pinion angle set, make sure axle is still centered side to side, tack weld perches to axle housing in several places. Remove axle housing from springs and very slowly weld perches to housing. Do not weld more than 1” at a time while letting housing cool to the touch before welding another 1”. Skip around when welding, otherwise you will warp the housing.

7) Reinstall axle using u-bolts and lower spring plates. The shock bolt points to the rear. Install shocks using original upper mounts.

8) Torque all bolts to the proper torque for there size. Retorque after 100 miles and 1000 miles.