New 3 point seat belts

Drewmac,

The reason I am going with the route I am going is the anchor point in the roof is solid and a proven attaching point with a lot of surface area forward and aft of the anchor point to absorb pulling force on impact which is why Chrysler used it in 1968/1969. I have a 69 notchback and a 67 notchback. No structural changes were made in this area except the addition of the anchor point about where the coat hook hole is on the 67.

Attaching the upper anchor point at the top of the quarter panel edge inner structure like that is a serious weak point. Theres not enough metal forward of the anchor point to absorb the load on an impact. None of us wants to think about the unthinkable, however when putting these things in your car, you have to think about the unthinkable. During a violent front or rear end collision. Depending on the impact speed, your body weight against an anchor point can triple your weight in force. Ex. a 225 lb man can exert 675 lbs on those anchor points on impact.

I used to work in the autobody industry and when repairing cars after impact damage we would replace the seatbelt assemblies that were used during the collision. They did their job that one time. However when I would remove them for replacement it was amazing to see how bent and twisted the retractor mechanisms were from being pulled against by a human body and the belts preventing it from flying through a windshield.

You can buy those convertable style shoulder belts and put them in a hardtop, but remember this, every aftermarket belt manufacturer has some lawyerese speak about how they arent responsible for the installation and use of them. Probably because of the non stock unproven anchor points. If they fail from a substandard mounting point and you eat the steering wheel they arent responsible. Plus they will interfere with the rear window cranks.