Manley Chevrolet Big Block Exhaust Valve Kit - 1.940in Head Dia. 5.422in O/A Length, 0.3110in Stem

Manley Performance is well-known for making strong internal engine components, especially for racing applications. This exhaust valve kit is a prime example, using their XH-428 material specifically chosen for its ability to handle the intense heat and stress found in high-performance gasoline engines. If you're rebuilding the top end of a Chevrolet big block and need valves that can take a beating, these are a solid option.

These valves are built tough. The XH-428 material offers nearly double the tensile strength at 1500°F compared to other common exhaust valve materials. They've also been put through rigorous fatigue testing, enduring up to 100 million cycles at high temperatures and stress levels, which is significantly more than many competing valves. The chrome stems and hard tips add to their longevity, while the swirl-polished under-head areas and machined combustion faces help improve airflow into the cylinder for better combustion efficiency.

This kit includes exhaust valves with a 1.940-inch head diameter and a 5.422-inch overall length, featuring a 0.3110-inch stem. When you're working on a performance engine, using well-made components like these Manley valves can make a real difference in reliability and performance.