After finding a location to place the Amphenol Series 97 plug I needed a way to mount it.  It would have been fairly simple to screw it to the frame rail except I had to mount it up close to the floor board to clear the air tank.  In this area the outside of the frame is not visible because the body overlaps it.  One slight mishap and the drill would be through the outer skin of the body.  Not a real good thing for the paint job.  The only bolt I could get at was one of the running board support bolts.  Of coarse this was near the lower edge of the frame and the plug needed to be close to the top.  The jog in it was necessary to clear battery cable.