[factorystock]

From 1967 thru 1971 there were 3 trim levels, the deluxe was the base model, the custom, and the super custom. In 1969 the Sierra and Sierra Grande models were added as a package of popular options, not trim levels. In 1972, GMC changed everything and now used 4 trim levels. Sierras and Sierra Grandes were now trim levels and not option packages. The custom was the base model, then super custom, sierra and sierra grande.