Is "Silverado" a Chevy moniker or a GMC one? Just asking because I have a 1978 Jimmy with the front end of a later model (the 4 headlights 2x2 stack formation). The dash label says Sierra Classic, but the on the rear quarter it has the Silverado tag. Oh, and the tailgate just say GMC Jimmy. Just curious if it can be a Jimmy Sierra Classic Silverado.?!?.. I know the Sierra Classic is GMC, but couldn't remember if Silverado was or not.