Tick Performance Valve Stem Seal Kit for Aftermarket Valve Springs in GM LS-Series Engines using stock powdered metal & bronze guides with separate locators. Metal Body Valve Stem Seals with Rubber Inside Skirt Fits an 8MM Valve Stem and a .500" Guide O.D. Stem: .277 Guide: .486 Width: .600 Height: .502 Brown & Black in color These high quality Valve Stem Seals are included in our Tick Performance .660" Lift Dual Valve Spring Kit for all LSx Engines. Contact our friendly sales staff with any questions you may have! Don't forget your Tick Performance Billet Valve Stem Seal Installation Tool for GM LS & LT-Series Engines for easy install!