I installed 3-point retractable belts in my '67 about a year ago. It has a bench seat out of a mid '90s. New lower outer holes had to be drilled and a reforcing plates put underneath. The center holes lined up, for the most part, but I had to make extentions out of flat steel, as the latch part was too short to reach through the seat if bolted directly to the cab floor. A correct year seat may not have those problems. Just remember to use the original, or grade-8 bolts everywhere. A broken bolt won't do any good in an accident. The belts I bought came with L brackets and bolts, which were helpful. I got mine through JC Whitney. About $90 each if I remember right, but you can get the non-retracting cheaper.
