Just a note, though the step side beds were unchanged (other then the floor and other minor running changes) between the 53 and the 80 something end of production, there is a difference between a step side bed length and a non- step side bed length. A step side bed was usually 7 1/2' long, but a 9' long step side bed was available off and on through production, the 9' beds are pretty rare.

The short box, non-step side bed is 6' long and the long bed is 8' long. The short bed standard bed, and the 'short" step side bed are different lengths. The frames are different, the bed to frame mounting points are different, and the position of the wheel wells in relation to the bed sides between the two styles are different.

If the truck you are looking at is a non-step side short bed, a step side bed will not interchange without some major modifications. Gene