Putting bucket seats in an F100 of that year is a challenge due to the fact that the floor slopes down toward the bottom of the doors. I had a set of bucket from a 70 Cutlass in a '73 F100 and had to get creative in mounting them. The inside rails can be bolted to the floor, but extensions will have to be fabricated to level the seat out for the slope of the floor. Mine were made from some flat stock angled at the bottom to match the slope of the floor. BTW, buckets from a '73 Comet recline and are pretty comfortable. I have a set in my '66 Mustang.