The Titan Motorsports billet main caps are precision machined from high tensile billet steel. We developed these main caps out of necessity for our 2JZ race program and soon found them to be applicable in most street engines. With the increased boost levels seen in single and larger twin turbo setups, the factory crank pushes down on the caps often leading to stress fractures and cracks. The factory main caps were not designed for the forces required when doubling and tripling the factory horsepower and torque levels. These caps are included in our short block and race engine packages and now available separately for those building their own engines. Titan Motorsports main caps will work with both the 2JZ-GTE engine found in the Supra turbo, as well as the 2JZ-GE engine found in non-turbocharged models. Please keep in mind that a line bore of the mains will need to be completed upon installation of these upgraded main caps. We recommend using brand new ARP Main studs and fresh bearings when installing the Titan Motorsports main caps.