[toast0]

Have you used aftermarket 3 point belt? A family member's Ranchero had them; the shoulder restraint slid into the lap belt near the buckle, but if you moved it would slip out. I can't imagine that being helpful in a crash, just a tethered weight to fly around.

[sokoloff]

I fitted the lap belts to my 'vert, which was already very much not-stock when I bought it, so I didn't feel bad making even more modifications (hydraulic clutch, modern T5Z trans, electronic ignition). There isn't a good, above-the-shoulder mounting point for the shoulder belt, unless you weld in a cage or mount one to an aftermarket seat.

The coupe is a close to correct C-code, which I've driven under 1000 miles in the last decade, so I've decided to leave it with period-correct 1965 belts that a prior owner installed rather than modify the B-pillar as my exposure isn't very high on that car due to very low annual miles.