AFAIK, Seat belts were NOT an option. They were mandated by federal law. What I'm really not able to answer is whether in 69 they were just lap belts, or whether they were three point belts. I have a 67 F/B and have owned 67 and 68 coupes also, and in all of them the belts are bolted throught a reinforced section of the floor pan, just behind the front seat, where the floor pan bends upward to become the transmission tunnel. You should see a hole in the floor pan at that location. that's for the adjustable buckle section of the belt. The other belt is the spring mounted unit that bolts to the inner frame rail just behind the seat, on the vertical portion of the frame rail.
Again, this is true of 67/68 models, I can't guarantee that's true on other years, but I strongly suspect that the mounting system was the same until they started supplying 3 point seat belts.
Hope that helps.
Jay67fast |