Do you happen to have those part numbers? I had a convertible that had those once and have a pair today that maybe those same units but I'm unsure.
I do not think the convertible had rear shoulder seat belts. The convertible did have optional shoulder belts for the front seats. The coupe did have optional shoulder belts for the rear two seats. They have different fastener mounts.
I took the belts off of a 70 GS 350 about a year ago,let me look for them,the rear and front should be there.Bruno.
Packerbacker I have no part number. Easiest way to identify them would be the mounting plate/cover and buckle.
John , A shot in the dark ! I would think that full size Buicks ( also Riviera ) had the same option and the same belts and hardware . Just a thought . Bil
So it takes a different package tray also? And that defroster is specific too? I thought all of the defrosters were same 1970-72?
I sold a 69 gs conv parts car years ago that had the rear shoulder belts. I had never seen them before. Good luck with your search
Here is a link to some information by George Nenadovich http://www.buickperformanceclub.com/RearShoulderBelts.htm