KIBBLEWHITE Racing Valve Spring Kit — 0.480 in lift, 340 lb open, 158 lb seat – 57-83 Sportster

Designed for its specific application, these racing valve springs are engineered with careful consideration of cam profiles, harmonics, natural frequency, valvetrain mass, required pressure, wire stress, fatigue life and engine rpm. 🏁

Progressively wound and heat treated, with shot peening for improved fatigue resistance and consistent performance across the rev range. 🔧

This is a complete set for one engine, built to provide reliable high-rpm valvetrain control.

Installation notes: may require machining of valve guides for special seals and may require "R"-style valves to achieve correct install height.

Kit includes four valve springs, four high-temperature retainers, four base washers and four keeper pairs.