the mounting point for aftermarket hitches are not the same as for the factory hitch - and even if the hitch is rated at 6000 lbs, if you attach it to a piece of paper, the overall rating will be of that piece of paper... since they do not attach to the points that OE engineers thought would be correct point of towing, the stress is put onto the elements that were not designed to take it, or outright to the sheet metal, which would tear up once any serious load is attached... the strenghth of the chain is determined by its weakest link...

what is he missing in reference to the harness?