Manley Chevrolet Big Block Exhaust Valve Kit - 1.725in Head Dia. 5.464in O/A Length, 0.3715in Stem

Manley Performance is known for making strong engine components, and this exhaust valve kit for Chevrolet Big Blocks is a great example. If you're rebuilding the top end of a high-temperature gasoline engine, these valves are built to handle the heat and stress. They are crafted from XH-428 material, which Manley says has nearly double the tensile strength at high temperatures compared to other common exhaust valve materials like EV-8.

These aren't just tough valves; they're also designed for improved airflow and combustion. The under-head areas are swirl polished, and the combustion faces are fully machined to help gases move more efficiently. Manley also put these valves through some serious testing, showing they can endure up to 100 million cycles under high stress and heat, which is a notable improvement over many other valves that might fail much sooner.

The kit includes exhaust valves with chrome stems and hard tips for added durability. While these are specifically designed for Chevrolet Big Blocks, it's always a good idea to double-check the exact dimensions and specifications against your engine's needs to ensure a perfect fit for your build.