Take a #ThrowbackThursday look back at some of the top contenders at the 1976 12 Hours of Sebring.

How times have changed in 40 years. In those days, there was no prototype category so the IMSA Camel GT Series was just that – run exclusively for GTO (2.5-liter and larger-displacement engines) and GTU (under 2.5L) grand touring cars.

Al Holbert and Michael Keyser claimed the overall win with their GTO class Holbert Porsche-Audi Porsche Carrera RSR, covering 230 laps in the 12 hours. A Porsche 911 S won in GTU, too, as Dave White and David McClain claimed class honors with a ninth overall finish. In fact, RSRs swept the first four places overall and standard Carreras the next two, beginning a 13-year winning streak for the Porsche marque at the grueling Sebring enduro.

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