 The Boss 429 engine was rated at over 370 hp.It featured aluminum heads, with huge, free-flowing intake and exhaust ports, a crescent shaped combustion chamber, and large oversized valves which were set at an angle so that the intake valve was close to the intake manifold and the exhaust valve was close to the exhaust manifold.The standard 735 CFM Holley carburetor was mounted on a high rise intake manifold.