For anyone building or rebuilding an engine, these Kibblewhite bronze bushings are seriously high-quality components. Made from solid U.S. mill-certified SAE 660 bearing bronze bar stock, they're built to handle the tough conditions inside performance engines. This bronze material is specifically chosen because it's highly resistant to impact, wear, and corrosion - exactly what you need when dealing with high spring pressures and impact loads. The anti-friction properties are excellent, and the machinability means they have a super smooth surface finish right out of the package. This 8-pack (part number 20-2106) gives you everything you need for your rocker arm assembly. Whether you're working on a performance build or just want the most durable replacement parts available, these bushings will stand up to the demands of high-RPM operation. Kibblewhite is known for precision components, and these bushings definitely live up to that reputation. They're tougher and more durable than standard bushings, which means better performance and longer life for your engine.