Manley Severe Duty® Valves deliver the ultimate in strength, reliability, and high-performance durability. Engineered for extreme gasoline engine temperatures, these valves are crafted from exclusive materials (XH-428 for exhaust and NK-844 for intake), offering unmatched tensile strength compared to competitive alloys. In fatigue testing at 40,000 psi and 1400°F, Manley exhaust valves endured 100 million cycles, while competitors failed after just 100,000, proving a 1,000× longer fatigue life. Each valve features chrome stems, hard tips, and swirl-polished underheads with fully machined combustion faces for superior airflow, efficiency, and wear resistance. Built for those who demand race-winning strength and precision, Manley Severe Duty® Valves set the industry standard for performance and endurance.
Manley Chevrolet Big Block 2.300 Head, .3415 Stem, .350 Longer Severe Duty Valves (Set of 8)
Severe Dty. BBC Int. Vlv Kit - 2.300 in. Head Dia.,5.610 in. O/A ,.3415 in. Stem
Swirl polishing and machined faces improved airflow/optimized efficiency
Exotic alloys for superior tensile strength, reliability, and longevity
Proven fatigue strength for extreme performance
Manley Valve - Intake, Valve-S/D 2.300,+.350.
Chrome stems and hard tips enhance durability
Manley Valve - Intake, Valve-S/D 2.300,+.350
Manley Valve - Intake, Valve-S/D 2.300,+350
Valve-S/D 2.300,+.350
Engine Intake Valve
Valve - Intake
