COMP Cams Camshaft CB 291T HR-107 MT ThDesigned to deliver an aggressive, hard hitting exhaust note at idle, the Thumpr camshaft series from COMP Cams also delivers excellent horsepower gains and a broad torque curve. A perfect choice for muscle cars and street rods, the Thumpr series' early intake valve opening and long exhaust duration create optimum overlap for that race car idle. The Thumpr grinds all require an aftermarket torque converter and lower gear ratio to ensure the drivetrain