Does anyone know where to purchase a 7" or 8" drop hitch with a capacity greater than 5,000 lbs? I have found a solid 6" drop hitch but it is not enough of a drop. I have a 7000 GVW flat bed trailer that does not sit level with the 6" drop. The trailer dealer that I went to did not have one in stock and was not able to order one with higher capacity. If they are not available what can be done?