The debut Camaro shared some mechanicals with the 1968 Chevy II Nova. Almost 80 factory and 40 dealer options, including three main packages, were available.

The RS was an appearance package that included hidden headlights, revised taillights, RS badging, and exterior rocker trim. It was available on all models.

The SS included a 350 cu in (5.7 L) V8 engine and the L35 and L78 396 cu in (6.5 L) big-block V8's were also available. The SS featured non-functional air inlets on the hood, special striping and SS badging on the grille, front fenders, gas cap, and horn button. It was possible to order both the SS and RS to receive a Camaro RS/SS. In 1967, a Camaro RS/SS convertible with a 396 engine paced the Indianapolis 500

source: wikipedia.org