the difference in the light truck fenders is just that the 57 has some mounting holes in the raised ridge around the grill opening, the 5&6 grill fits inside the opening, the 57 sits on top of that surrounding ridge otherwise identical and can be interchanged ... 4100 and up = 1.5T and up - different fenders than the light trucks, useing about the same grill all years and it fits inside the opening, so yes all 3 years the same
take a walk thru the gallery and note the difference in light/heavy trucks of those years
Bill
