The stock seatbelts from my '73 no longer retract (gee, big surprise). And, even if they did still work, just based on age, and the fact that I'm restoring the car anyway, might as well replace them. So, I spent about 2.5 hours last night researching options and ran across the numerous threads about the pros/cons of harnesses versus regular old 3 point belts for street cars. This was an interesting read for me and led me to other research on the net as well.
It seems like the biggest issue with the 4 point system is submarining.
It seems like the biggest issue with the 5 point system is retention in the event of a rollover with resulting spinal compression. Thus, some only advoacte their use with a cage.
It seems an issue with all harness systems is increased possibility of neck injury.
We all know the issues with 3 point systems.
I also did additional research on the net and found it interesting that both Ford and GM are doing research on, and advocating for, 4 point systems. However, these appear to rely on air bags and tensioners for proper/additional safety.
I like what I see of the Schroth street-legal 4 point system. I think it provides more protection than a 3 point and the ASM technology may allow the body to move enough to prevent compression in a rollover and the neck injury issues minimized; if I read it correctly. This seems to be about as all-encompassing a solution as I see for a 914 street car. And, at $150/per brand new, is similar to stock replacement. I don't necessarily want to reopen an apparently, been there done that debate, but am interested on thoughts on this system.
Also, can holes be cut into the back of the stock seat so as to use the Schroth street-legal harness? Schroth states on their site that a fixed headrest seat is a no-no with their system. It would seem a similar problem would exist with any harness and stock seats. (I like the look of the stock seats) Or, do stock seats necessitate stock-style seatbelts?