my truck had a 3 window cab , I since found a 5 window in much better shape. my truck is registered as a 51. Changing the cab theroretically could change the year model ? No ID. plate. Depending on the doors (vent / non vent) that i put own it could be a different year model? So what really determines the year model characteristics of the truck ? also some people weld up the vents and cowls so how do you really classify if po changed some of these things ? I still have my orig ID. plate with 51 ven code
