Manley Chevrolet Big Block Exhaust Valve Kit - 1.900in Head Dia. 5.522in O/A Length, 0.3110in Stem

This kit includes Manley's Severe Duty? exhaust valves, specifically designed for Chevrolet Big Block engines. These valves are crafted from XH-428 material, a unique alloy that offers nearly double the tensile strength at 1500°F compared to other common exhaust valve materials like EV-8. Each valve measures 1.900 inches across the head and has an overall length of 5.522 inches, with a 0.3110-inch stem diameter.

Manley's Severe Duty? valves are built to handle extreme conditions, proven through rigorous fatigue testing. They endured up to 100 million cycles at 40,000 psi and 1400°F, a performance level that significantly outlasts many competitors. The design includes chrome stems and hard tips for added durability, along with swirl-polished under-head areas and fully machined combustion faces to promote better airflow and combustion efficiency. This makes them a solid option for high-temperature gasoline engines where reliability under stress is critical.