COMP Cams Camshaft A8 299THR7 Thumper

This COMP Cams Big Mutha' Thumpr camshaft is designed for AMC 290, 304, 343, 360, 390, and 401 cubic inch V8 engines. You get the camshaft itself, which is a hydraulic roller type with a 243/257 duration and .550/.550 lift. This camshaft is intended for street/strip applications and is known for producing a very aggressive, hard-hitting exhaust note at idle, often described as a rough idle. It’s a popular choice for muscle cars and street rods looking for that race car sound and significant horsepower gains.

To make the most of this camshaft and ensure your drivetrain stays in its powerband, it requires several supporting modifications. You'll need an aftermarket torque converter with at least a 2800 RPM stall speed, lower gear ratios in your rear differential, and an upgraded intake system. Additionally, the Thumpr camshafts typically reduce vacuum at idle, so vehicles equipped with power brakes will need a vacuum canister, pump, or hydroboost system to maintain proper braking function. This camshaft also requires a minimum of 9.5:1 compression ratio to perform optimally.

This camshaft fits a wide range of American Motors and Jeep vehicles from the late 1960s through the early 1990s, including models like the Jeep CJ series, Jeep Cherokee, and American Motors Javelin. For best results and to ensure proper operation, it's recommended to consult the manufacturer's installation instructions for specific details regarding setup and required components.