Open the rear doors and look to see if you have either an open hole next to the bottom latch for the left rear door,( at the tail pan area) or you have what looks like a bolt with a recessed square head. Look under the truck for a piece of 1.5"x 1.5" angle stock that is riveted to the frame rails just behind the rear axle. Attached to that should be a channel piece that is slanted downward toward the rear of the truck and is also bolted to the rear cross member. I'll email you photos of the rest of the assembly.