3rd generation bumpers

1970 Rear Bumpers

70s do not have the backup light holes in the bumper. Try OPG (Original Parts Group). www.opgi.com Good Luck! :beer:

the backup light holes turn into parking lights and instead have red lenses after 1968. Everything should be the same size.

1970 rear bumpers have 2 rectangular holes. The holes have a metal housing with a red lens, no bulb, just acts as a refelecter. The backup lights are in the tailgate.

I have a 69 with two reflectors in the rear bumper. The reverse lights are in the tailgate. I wish they were in the bumper though.

Late post but just an FYI
You could get a 67-68 bumper and but a "tail gate skin cover" for the gate. Makes for a nice smooth look.
I bought a 69 that the PO had put a 68 rear bumper on, so it has backup lights in both bumper and tailgate. I like them in the bumper, so I am going to buy a "tail gate skin" and run with a smooth rear gate