Manley Chevrolet Big Block Exhaust Valve Kit - 1.600in Head Dia. 4.921in O/A Length, 0.3415in Stem

If you're working on a Chevrolet Big Block engine and need exhaust valves that can handle serious stress, this kit from Manley Performance is a solid option. These are specifically designed for high-temperature gasoline engines, meaning they're built to last in demanding conditions where stock parts might falter. The exhaust valves are made from XH-428 material, which Manley states has nearly double the tensile strength at 1500°F compared to other common exhaust valve materials.

Beyond the material, these valves feature chrome stems and hard tips for added durability, and the under-head areas are swirl polished to help improve airflow into the combustion chamber. Manley also mentions that their Severe Duty valves have undergone extensive fatigue testing, enduring up to 100 million cycles at high temperatures and stress levels where competitor parts failed much sooner. This level of testing suggests a well-built component designed for longevity under heavy use.

This kit includes the exhaust valves with specific dimensions: a 1.600-inch head diameter and an overall length of 4.921 inches, with a 0.3415-inch stem diameter. If you're rebuilding or upgrading your engine's top end, these valves offer a strong material choice and construction details aimed at improved performance and durability.