The AD engineering kit uses square tubing cut and welded on an angle and then welded to an upright to bolt to the frame. Kind of a bent L shape ordeal.
I'm just getting to this point on ours and plan to use some 1 x 2 tube stock with a plate on top to make up the angle of the board. This will be welded onto some flat stock with gussets to bolt to the frame. that way I can bolt the running board to the plate, bolt the tube stock to the frame rail, and then put a tack on it for alignment and then on to finish weld. I hope to have this in the next week or so.
