Quick Install Adjustable pushrods + lower pushrod covers and upper pushrod retainer clips + 4x pushrods with 3/8" (9.53mm) chromoly OD tubes and 0.134" (3.4mm) wall thickness. Individual length Exhaust and Intake pushrodsInstalls without the removal of rocker covers. See Feuling 566072 for replacement pushrods only; 963228 for replacement pushrod covers only of this complete Feuling 707323 pushrod & pushrod cover kitThis is the strongest ‘Fast Install'' pushrod on the market! The strength and rigidity of this quick install pushrod is second only to heavy duty one piece pushrods. Our tube material starts out as 7/16" rod OD; it then gets turned down to 3/8" OD leaving heavy duty 7/16"–20 threads for the base and jam nut. The jam nut slides up the pushrod; the base then loosens up into the pushrod to shorten length and allow quick install access. Note: The supplied chrome lower pushrod covers and retainers are to be used with your stock inner/upper pushrod cover components as inner tubes; cups; springs and washers.