High Compatibility: Norris NSR 5.3 cam kit, compatible with Norris trucks 1999-2013 GM Gen3/4. It fits LS truck engines and is suitable for 4.8L, 5.3L, 6.0L, and 6.2L engine displacements. Precision Restoration: Engine camshaft kit OE: 12625437, SP011-16. Fully matches the original part. The kit does not include springs. Enhanced Wear Resistance: The ls cam kit is made from durable grey cast iron, offering wear resistance and fatigue strength, capable of withstanding thousands of impacts per minute in the engine, reducing wear on the contact surfaces between the cam lobes and lifter pillars. Increased Strength: After high-frequency hardening, the ls camshaft replacement has higher density and hardness, enabling it to resist the corrosion of engine oil and coolant in harsh operating conditions. Restore Engine Performance: Our engine cam systematically addresses performance degradation and wear caused by engine aging, extending engine life, and improving overall performance.