I dont know why but the 6'6" bed hitch and the 8' bed hitch have different part Numbers can anyone verify that they are in fact different and mount differently? would thik they are the same 99-2007 receiver hitch . for the 2500 silverado. found a killer deal online from www.gmpartsclub.com for the factory part # 12497968 which they say is for my 6'6 bed but i found online a used perfect condition part #15106792 which pulls up the same year but for teh 8 foot bed. i would think they mount exactly the same and are the same hitch ? anyone, anyone, anyone?