Basewasher (OEM Replacement), HT Steel, IN/EX, HD® Shovelhead 74", 1966-1977
KPMI® Basewashers are designed to safely control lateral movement of the spring and to set the correct valve spring installed height for each valvetrain system. The ID is close to a net fit on the valve guide, allowing just enough clearance for an oversize guide. The shoulder diameters are designed to fit the spring correctly. The steps are designed with specific radii called out in each corner so there are no sharp edges. Each basewasher has been engineered to maximize its mechanical strength using FEA design software.