This dealer option was installed for people who were not comfortable with the height of their seats. This same kit was used on many intermediate Ford Products from 1965-1970. One kit does one bucket seat or one bench seat.
Ford part # C6OZ-6362016-A.
Click on images to enlarge.
The screw on clips were included in the kit so the spacer would stay in place as the seat was guided into the four holes in the seat riser. Often these clips are cracked or missing and we cannot guarantee all four will come with the kit you order. A similar clip is available new but is is not too hard to install the seats without them in place.
Here is what many of the clips look like. Notice the extra length of the seat track mounting screws. They have a total length of 2 1/4".