Manley Performance LS & LT NexTek? valve spring kits take the guess work out of making your valvetrain race-ready. Engineered for maximum durability, stability, and precision in high-performance and racing applications, these chrome-silicon alloy springs provide exceptional fatigue resistance and high-tensile strength, ensuring consistent valve control at extreme RPMs. Save time and money with these all-inclusive kits, featuring premium springs, retainers, I.D. locators, locks, and Viton? seals.