I was trying to order the rear leaf spring bumpers to replace the old ones. Is this the correct setup for a 46? I looked in the manual and I didn't see a top spring. The two mounts hold a square rubber bumper. The "L" looking bracket mounts to the knee action shock and the other flat plate mounts the frame.I got a new semi circle that mounts to top of the u bolt for the bottom spring but we don't have those. What is installed on the truck come from a different year? If so what year?