the part number i got from seatbelt planet for the rear 3-point belts of my 84 is 5031355. When ordering, I talked with Mike Mills at Seatbelt Planet and he was super helpful. The passenger side rear belt went in really easy if you follow this thread. Haven't gotten to the driver's side rear belt yet, but looks to be more difficult with the wiring where it is.this cross my brain when i first looked at that website...