This replaces the factory flywheel/flexplate with an improved billet one-piece design, eliminates the heavy cast iron and the weak stamped steel flex plate. This is a must with the high torque in conjunction with a better-designed torque converter that can transfer the torque with no slip. The flex plate is bolted to the crankshaft, then the converter is bolted to flex plate. The torque from your is transferred to the flexplate, from the flex plate to the torque converter then to your input shaft in the trans. With increased torque from the engine and no slip out of the converter, it can crack and/or rip the center out of a stock flex plate.