I double checked the code in my source book, I come up with the same information as Micheal. I'm going to venture a guess, and say thit your truck may not have the original cab on it. I'm not sure if they still stamped the serial number on the chassis on the '60 and later trucks like they did with the '55-'59s, but it may be worth looking to see if it has one on it. Unfortunatly, the serial number will not tell you what bed the truck originally had.