As one who depended on his 3 point belt to do the right thing in my '57 GMC, I would not use the seat as an attachment point for the belts.


My shoulder mounting points had a piece of 1 1/2" by 8" of 3/16" flat steel bent to match the curve of the inside of the cab with a 1/2" hole in the center with a welded on nut for the belt pivot.

The lower outside mounting points had a 4"x4" square plate on the outside underneath of the foot well of the cab entrance.

I don't have a picture of the center belt attachment. It was one 4"x12" piece of 1/4" steel with a 1/2" hole drilled near each end for the short center belts.

Tested the system in October of 2012. I ended up hanging upside down in the belt with a scratch on my elbow and needing to change my underwear.
Attachments
1.jpg (82 KB, 93 downloads)
2.jpg (73.83 KB, 94 downloads)
3.jpg (23.62 KB, 95 downloads)
4.jpg (54.97 KB, 95 downloads)

Last edited by Bill Hanlon; 06/07/2024 4:38 PM.
'57 GMC 102, Original 347 V8, HydraMatic, 3.08 rear gear, added A/C, disk front brakes, HEI, AFB carb, '98 Honda Black Currant paint. T-boned and totaled 10/12
'52 GMC 152 Stake Bed, Original 228, SM420, added A/C, HEI, disk front brakes, '67 Chev 3.55 rear gear. Gets used as a real truck.