I have been looking at Screws for several months at local dealers. Seldom, almost never do I see one with the 4.6. They are all 5.4's. A local dealer told me that the 4.6 Screws are difficult to sell and they only order them by request. He said everyone wants the 5.4. Is the 4.6 lame for that weight truck? Does anyone know the weight diffence between a Supercab and a Supercrew?