Manley Chevrolet Small Block Exhaust Valve Kit - 1.500in Head Dia. 4.911in O/A Length, 0.3415in Stem

If you're rebuilding the top end of your Chevrolet Small Block engine and need exhaust valves that can handle serious heat and stress, these Manley Severe Duty valves are a solid choice. They're specifically made for high-temperature gasoline engines, meaning they're built to last even when things get hot under the hood.

These aren't your average valves. Manley uses XH-428 material for the exhaust valves, which has nearly double the tensile strength at high temperatures compared to other common materials like EV-8. They've also put these valves through rigorous fatigue testing, enduring up to 100 million cycles at 1400°F, which is a remarkable difference compared to many other valves that fail much sooner. The stems are chromed for extra durability, and the under-head areas are swirl-polished to help improve airflow into the combustion chamber.

With a 1.500-inch head diameter and an overall length of 4.911 inches, these valves are designed to fit specific Chevrolet Small Block applications. The 0.3415-inch stem diameter is also a key measurement to ensure proper fitment with your valve guides and retainers.