The installation of this seat belt is very easy. The welded and reinforced mounting holes for the lap portion of the belt were installed when the car was built. And as some already know, the third mounting position was also installed when the car was built.
This third mounting bolt can be viewed from the inner rear fender well. On the inside it is covered by the interior vinyl, and the outside, the hole is plugged with a plastic plug.
Scoring the vinyl with an "X", after locating the plastic thread plug, allows for easy removal.
The inboard mounting point, with the red release button is mounted first.
The belt snugness is normally adjusted by pulling on the end threaded through the lever release buckle slip-clamp. The lap/shoulder loop feed-thru slip-clamp allows the lap belt slip-clamp to be tight, and shoulder as slack as desired. These two can be used, in combination, to alter lap and shoulder lengths by altering length of lap belt, and hence length of shoulder strap. One counterbalances the other. Adjustment is normally made at the buckle end. The shoulder feed-thru is a cinch type, and allows the lap buckle centering to be as desired. However, the shoulder strap slack can be separately adjusted at it's own slip-clamp mount in area behind the seat. It can accommodate a wide range of girths without adjusting the shoulder belt length again, by merely allowing the belt center to be moved as i's length is changed, as is the shoulder slack. Beyond this, a re-balance of the two cinch points is required, but easy. Initially, some fiddling is required, but once done it is seldom that the rear belt adjustment need be changed.