BTR’s .660″ lift Platinum spring is our most popular and successful spring to date! Each spring pair is polished for a beautiful look and ground to exact flatness and finish. Beware of chrome-plated imitators! Extreme durability and consistency means that you can rev up without worry, with hundreds of thousands of miles, passes and testing hours we’re sure you’ll be impressed. Designed for use with OEM style rocker arms in LS/LT applications.