When I was a kid, most seat bealt were lift latch type but some were crap since they were friction type latches. The had teeth that would hold against the webb material only. Those were unsafe in any form of accident. Metal to metal interlocking latches became standard when governments started regulating them. I still use a friction type seat belt to hold the bottles in my oxt acetylene cart. That's about all they are good for.
Wesco has the threaded mounting plates and instructions. http://www.wescoperformance.com/retrofit-seat-belts-shoulder-mt-door.html#top
Re-using OEM or any other belts is not advisable. You never know what stresses, aging, chemicals released in an accident, weathering,etc might have occured before you got them. Damn, a set of DOT approved,chrome latch belts, including the extra bracing plates (for lap belts) is about $70. Why take any chances when they're this cheap?
i think i found a great cheap alternative to 3 post belts! check this out. http://ezonpro.com/e-z-on-86y-universal-harness/. put in a lapbelt, then an anchor point in the middle to connect the clip to. should work with a a standard booster, but il have to make sure that clip will reach all the way over the seat, down to the floor.
it says tested , but see if its approved first . as lots are tested and not approved . if its approved it will have a sewn on tag on it saying so .
I fit seat belts as part of my job. Our standard plate sizes are 1 5/8''x 4''(40mm x100mm) and2''x3 1/8''(50mm x 80mm) and all 1/8'' thick. These are fitted as doubler plates and have a 7/16'' UNF nut welded on and our standard specifies grade 5 bolts. The plates are riveted together . The spacings for the lower points are no wider than 19 3/4''(500mm) and no less than 13 3/4''(350mm), any wider they start to loose effectiveness and any less they will start to crush you on impact. The top point should be just behind your shoulder and not below the shoulder (average height) as if its too low the belt will crush your spine. Just a couple of pointers. Cheers, JW
In my 39 Deluxe coupe I uses Julianos belts and the floor mounting pieces as well. They have both a modern and and old style latch type as well. They are approved for safety as well. In my convertible I used seat belts from the donor seat cr an 84 Olds Totonado.
The Jalopy Journal
