Expounding on what Simplyconnected and Sidewalkman posted below:
The top loop securing the shoulder belt at the top of the seat back (like pictured on this 2005) was something I extensively explored many years ago with my 56. This could easily be done as the seat back panels are removable, steel extended up to secure a holder of some sort.
The next issue was to make the seat back lock into position and not flip forward. I'm sure that would be possible too, but thought I would engineer that later. A mount for the belt at the floor would not be a problem.
The info I was finding all related to the distance of this retainer to the center of a persons ear. To be effective in holding a person back and not induce downward pressure the upper loop should be above the shoulder approximately at ear level for someone of average height.
I am 5' 11" and in my daily drivers this retainer is mounted on the "B" pillar at or just above the center of my ear. I would suspect the 2005 pictured has high seat backs placing this retainer near the driver's ear level.
On the 57 my ear is 10" above the seat back and 9" above on the 63. A loop mounted and looking like the 2005 on these old and low seat backs will induce downward pressure. I do not own a Squarebird but would guess the measurements to be similar for someone my height. It would be interesting to have an owner of a Retro bird sit in the seat and measure the vertical distance from the center of their ear to the loop.
I have also seen the shoulder belts added with retainers bolted through the roof, with a chrome cap visible on the outside. Effective, but not attractive and I would wonder if the bolt would tear out of the roof skin in an accident?
I am proof shoulder belts work and believe in them. I had a new Yukon for 3 weeks when a Grand Marquis pulled out in front of me. I hit him at about 45mph, totaled the Merc and I never hit the airbag! (Yukon had about $11,000 in damage) The shoulder belt stopped me and I was very slightly sprained but unhurt. I'm all for this modification, but more thought needs to be put in the project before just bolting something in.
Hope Dad's58 supplies us with pictures.
Last edited by Joe Johnston : 02-28-2017 at 12:17 PM.