anyone converted to a retractable front seat belts- 70 Dart swinger Bench seat

Please see my thread about Wesco performance seat belts I bought in the body section I believe it will detail my install a lot better. The blue car which is not mine is also a barracuda notchback I have a 67 notchback in a 69 notchback if your car already has a shoulder belt attached point in the roof you only have to add 2 attach points in the floor the pictures on my thread detail that better as far as making an attached point and where to put it