Manley Chevrolet Small Block Exhaust Valve Kit - 1.625in Head Dia. 5.021in O/A Length, 0.3415in Stem

If you're rebuilding the top end of your Chevrolet Small Block engine, especially for high-temperature gasoline applications, these Manley Severe Duty? exhaust valves are a solid choice. They are specifically designed to handle the intense heat and stress found in performance and racing engines, offering a significant upgrade over stock components. The 1.625-inch head diameter and 5.021-inch overall length are key dimensions for proper fitment in many popular Small Block heads.

Manley uses their exclusive XH-428 material for these exhaust valves, which has nearly double the tensile strength at 1500°F compared to other common exhaust valve materials like EV-8. This well-built material, combined with chrome stems and hard tips, means these valves are made to last under extreme conditions. The swirl-polished under-head areas and fully machined faces help improve airflow into the combustion chamber, contributing to better engine efficiency. Rigorous fatigue testing shows these valves can endure up to 100 million cycles at high temperatures and stress levels, far outperforming many competitors.

These valves are a critical component for anyone looking to maximize the performance and longevity of their engine build. Ensure you have the correct valve spring and retainer combination to match these robust valves for optimal performance.