The motor plate is designed to bolt between the water pump and the engine block and make installation and removal of the engine easier. The trapezoid shape allows this one piece design to strengthen the front of the chassis. Material is ¼" thick 6061-T6 aluminum, computer-machined to accurately match the engine. Extra-large-sized trapezoidal-shape (39x30x12") will fit Olds 455 engine applications. Shipped complete with hardware and mounting tabs.