PORSCHE 911 – INTERNATIONAL RACE OF CHAMPION 1973. – Nº 2. M. DONOHUE.
The 1973-1974 IROC was contested over four races, two at Riverside in October 1973 and two at Daytona in February 1974.
The overall winner was Mark Donohue who claimed the win by the sum of winnings ahead of the sum of points.
