Manley Chevrolet Small Block Exhaust Valve Kit - 1.625in Head Dia. 4.911in O/A Length, 0.3415in Stem

This kit includes Manley's Severe Duty? exhaust valves, specifically designed for Chevrolet Small Block engines. These valves are crafted from XH-428 material, a high-performance alloy chosen for its exceptional strength at high temperatures, making them well-suited for demanding gasoline engine applications. Each valve features a 1.625-inch head diameter and a 4.911-inch overall length, with a 0.3415-inch stem diameter.

Manley's XH-428 material offers nearly double the ultimate tensile strength at 1500°F compared to other common exhaust valve materials. This robust construction, combined with chrome stems and hard tips, contributes to enhanced durability and longevity. The under-head areas are swirl-polished to help improve airflow, and the combustion faces are fully machined for better efficiency. Rigorous fatigue testing shows these valves can endure up to 100 million cycles under extreme stress, significantly outperforming many competitors.

These valves are a solid option when rebuilding the top end of your Chevrolet Small Block, especially if you're looking for improved performance and reliability in high-temperature conditions. Always refer to the manufacturer's installation instructions for proper fitment and assembly procedures.