This harmonic balancer installation tool is specifically designed to be compatible with Chevrolet small-displacement engines (SBC) and large-displacement engines (BBC), including the popular Chevrolet 350 crankshaft. It can directly replace tool #66515 and greatly simplifies the installation process. This tool is made of high-quality materials, including heat-treated steel, corrosion-resistant galvanized nuts, and lightweight aluminum washers. This combination ensures its durability and allows for long-term performance even after repeated use. Using this tool is very simple: Insert the corresponding end into the crankshaft, then rotate the nut to firmly fix the vibration balancer in place. The included thrust bearing helps reduce friction during the installation process. This kit is perfect for DIY enthusiasts and professional mechanics. It contains all the necessary components - threaded rods, nuts, washers, and thrust bearings, making it a practical addition to any tool collection.