If you're still running the bench you'll need to fab up something for the shoulder mount... I haven't got to that stage, but I plan for it. My idea is to bend up and 1.5" hoop that rises just below the rear window. I have to figure out and measure from the donor seats for heights and widths. also gusseting them into the body at the floor with plate steel as to not get torn out at the body mounts. You have two on each side that can be tied into. Problem I see is getting around the fuel tank. Some creativity can be had here... Wish I was further along to give you a pic.
Seat belts are engineered for specific angles. they seem to bee overlooked all the time. but when you need them, they better work... I come from the rock crawler side of things, but safety systems can't be thrown together. Look into aftermarket 3 point systems and see the requirements. Then look at what is possible in your situation...
Not the help you wanted, but food for thought....
-Jerry
After searching for a year I found the next project!
46' 1/2 ton in pieces! took 2 trips to get it home, but most of the hard work was already done!!!
-jerry
"Phil" the 46' 
