A friend of mine has a 91' K5 with stock shoulder belts for the rear seat. If all you want is shoulder belts, maybe you should try to find these from a 91' model. These are bolted to his hard top/floor. They are not "integrated" in the seat like the yukon/tahoe so this ads a couple more bolts to deal with when removing your top. I'm not sure if that was an option on other years like 89' 90'??? Good luck...