Spring Kit .600 Lift Tc '05 10 Evo Sportster '04 11

Wound from Premium Kobe Super-Clean Chrome Silicon Wire. KPMI valve springs are heat-treated, stress relieved and shot peened to insure maximum performance and life. Springs are engineered for each specific application using proprietary advanced spring design simulation, and analysis software. Engineers pay special attention to cam and spring harmonics, stress, mass and operating rpm.