I think it all depends on what roll bar you have. I have had 77-79 jeeps that had 3-point shoulder strap belts and I have had jeep of the same years have just lap belts. Somewhere in late 70,s early 80,s (I used to know) jeep switched types of roll bars, the earlier style just sat, and bolted on top of the rear fender well and the lap belt was bolted to the seat mount bolts. The later style of roll bar, just the back portion sat on top of the rear fender well, and the front down bar ran in front of the fender well and mounted to the floor. The one that go,s to the floor should have previsions for mounting a 3-point belt, the other style you have to decide where and how to mount the 3-point belts on your own