I happened to have some seat belts for another vehicle that came from a place called Chevy Duty. They were a perfect bolt-in for my LJ-20.
http://www.chevyduty.com
The belt kits come in several colors and include a bolt that fits the pre-drilled and threaded holes in an LJ-20. They also have a shoulder belt type with retractor that looks like it might work if you have a roll bar to attach the top part to.
Seat Belts
Moderator: stevec