I put a set of the XV seatbelts in my 70, and they used the stock mounting holes. It was pretty straightforward. The molded plastic sleeves on the front inner belts are contoured in a way that makes them "bend" the wrong direction, but it isn't too noticeable with the seats and console in. The retractor at the outside rear of each front seat sticks out far enough that it contacts the seat if it is in the full back position. Overall, I think they were a great improvement over the stock belts. They went in after the new carpet and headliner, so I didn't have to deal with existing holes where the stock belts came through. In the month and a half that I have had them installed, not 1 person has noticed that they are not stock. Except of course my wife, who sees the credit card bill.