Rocker Shaft Shims (pkg. of 30)

With any performance type aftermarket roller rockers, it is necessary to "set up" the valvetrain. Because of different cylinder heads/tolerances/past machine work, etc, the exact positioning of the valves can vary slightly. A large part of setting up a performance valvetrain involves using these shims to check and adjust the wear pattern of the rocker tip. This can be thought of as how the rocker "wipes" across the valve face and back. Adding, and/or subtracting these shims underneath the rocker shafts allows you to setup this spec. the way you want it. We offer these shim packages for this purpose. One package includes 30 shims total, quantity (10) .010" (ten thousandths thick) shims, quantity (10) .020" (twenty thousandths thick) shims, and quantity (10) .030" (thirty thousandths thick) shims. Use these in conjunction with the correct spacers and shaft holddowns to position the rockers where they need to be. We recommend using these with all of our aftermarket roller rockers, as well as rockers from other aftermarket companies.