Spring Shims .015x.520 IDx1.300 OD GM LS Series

The Spring Shims .015x.520 IDx1.300 OD GM LS Series by COMP CAMS represents precision engineering for serious LS engine builders and performance mechanics. These hardened steel shims are essential when fine-tuning valve spring installed heights on GM LS platforms, ensuring optimal valve train geometry and preventing catastrophic engine failure from over-compression or under-compression. Whether you're rebuilding a stock LS engine, installing aggressive camshaft profiles, or increasing boost on a supercharged application, correct shim selection is non-negotiable for longevity and reliable power delivery.

Manufactured to COMP CAMS' exacting tolerances, this .015-inch thickness shim features a .520-inch inner diameter (ID) and 1.300-inch outer diameter (OD), designed to stack under factory or aftermarket valve springs on LS cylinder heads. The thin profile allows stacked combinations to achieve precise installed heights—typically 1.550 to 1.700 inches depending on camshaft lift, spring rate, and load specifications. COMP CAMS' hardened steel construction resists deformation under sustained spring pressure and thermal cycling, eliminating spring surge and maintaining consistent valve control across the entire RPM range. Proper installed height directly controls valve seat pressure and prevents valve float on high-lift cams.

These shims are essential for any LS engine modification involving cam swaps, turbo or supercharger installation, or increased fuel mapping. Mechanics and engine builders routinely use multiple shim thicknesses in combination to hit exact specifications during head assembly. The compact 1.65 x 0.65 x 4.2 inch package makes storage and organization simple on the shop bench. Compatible with all GM LS1, LS2, LS3, LS7, LSX, and truck LS platforms, these COMP CAMS shims (MPN 4717-16) are a mandatory detail item for anyone serious about LS performance and reliability.