Offering General Motors extras has always been a way their franchised dealers could add to their income. These are referred to as accessories. Extras available during production are options.
Because trucks in the early years were bought for work (not like most cars) buyers purchased very few accessories. Thus, most GM truck accessories from these years are very rare! Hood ornaments are an excellent example! They added nothing to the hauling ability of the vehicle. Still, GM made them for their dealers just in case a buyer might want an appearance extra like the passenger cars all had when they left the factory.
Both Chevrolet and GMC offered their own individual hood ornaments, both being different from the other. The following shows the hood ornaments for the two marques during 1955-1957.
1955-56 Chevrolet [now reproduced]
1957 Chevrolet [now reproduced]
1955-57 GMC [not reproduced]