The Titan Motorsports billet main caps are precision machined from high tensile billet steel, developed to meet the demands of high-performance 2JZ engines. Designed to address the limitations of factory main caps under increased boost and power levels, these caps provide enhanced strength and durability for both race and high-powered street applications. Suitable for both the 2JZ-GTE (Supra turbo) and 2JZ-GE (non-turbo) engines, installation requires a line bore of the mains. For optimal results, use with new ARP main studs and fresh bearings.