COMP Cams 1.640" O.D. Spring Shim Kit 931121 A urethane plug is also

A urethane plug is also included if you wish to block off the auxiliary air inlet

000 psi and precision machined for optimum thread engagement

digressive piston which reacts to changing road conditions

Direct Replacement Part

5 Ford Mustang

COMP Cams 1.640" O.D. Spring Shim Kit 931121 A urethane plug is alsoThis shim kit contains . 015", . 030" and . 060" thick Valve Spring Shims with 1. 640" outside diameter and . 635" . 650" inside diameter are used to equalize the installed height of valve springs. Made from the highest quality shim stock, these shims are heat treated to stand up to radical cam lobes. Kits are also available. This COMP shim kit includes a number of 1. 640" diameter shims of various thickness. This kit includes 16 . 015" thick shims,