Abstract: A door and running board conversion kit including a hanger framework capable of mounting beneath several different vehicle chassis configurations. A step device is adapted to be supported longitudinally on the hanger framework, and which carries a step deck to be spaced at a selected distance below the bottom edge of a vehicle door and terminating in a longitudinal outboard edge. Such edge is to be covered by a downwardly projecting door skirt fastened to the outboard lower extremity of the door to project downwardly a distance equal to or greater than such selected distance to projection in covering relation over the outboard edge of the step deck when the door is in a closed position.