2207HKR Hooker Super Competition Long Tube Headers - Painted. 1967-1969 Camaro, 1968-1974 Nova: 265-400 Tube 1.875" O.D. x 30", Collector Size 3.5" O.D., Collector Length 10", Port Shape: Rectangle. With Hooker Super Competition the objective has always been to make the maximum horsepower and to put it at the optimum point in the power curve.