Spoke with DG tailgate and have the 3 length set, he mentioned to ensure stock cables are not slack as the arms and latching are not to take all the load. With my 8 ft box, the tires go a bit beyond the bed and the tail gate doesn't fully close, so the shorter arms keep the gate from bounching. If I had a 6 ft bed, I would tend to like the idea of 2x10s joined with plywood or a few 2x 8s given the cost of the machine. The cross members would give something to strap the ramps to and keep them from shifting . The one at the cab end could help serve as a wheel stop. By the way, the DG guy was good on customer service, first set was wrong order, and he sent the correct set and return label without waiting for the return of the wrong order.