Manley Chevrolet Small Block Exhaust Valve Kit - 1.625in Head Dia. 5.365in O/A Length, 0.3415in Stem

If you're rebuilding a high-performance Chevrolet Small Block engine, especially one that sees extreme conditions, these Manley Performance Extreme Duty Series exhaust valves are a solid choice. They're built to handle the intense heat and forces found in applications like Top Fuel drag racing, marine engines, or even restricted carburetor circle track racing. These aren't your everyday valves; they're designed for engines pushed to their absolute limits.

The key to their durability is the XH-432 XtremeAlloy material Manley uses for the valve itself. This alloy is known for its exceptional resistance to heat and stress. On top of that, the valves feature chrome-plated stems, which helps reduce friction and wear inside the valve guides, and hard tips to stand up to aggressive valvetrain action. Manley also puts a lot of attention into the airflow characteristics. The under-head area is swirl-polished to help smooth out the air path, and the combustion face is fully machined to ensure it seals well and contributes to efficient combustion.

When you're building an engine that needs to perform under extreme pressure, using components designed for that kind of duty makes a big difference. These valves are a testament to that philosophy, offering a well-built solution for demanding engine builds.