ATP Z-460 Improved Heavy Duty Automatic Transmission Flex Plate is designed to connect the engine and transmission. Most flex plates are made of a thick piece of sheet metal with bolt holes for the torque converter and teeth for the starter. The job of a flex plate is to allow for expansion of the torque converter as engine RPM increases. The constant expansion and contraction of a flex plate over time can result cracks and/or shearing of the flex plate. A damaged flex plate can create serious (expensive) damage. Broken flex plates cannot be repaired; they must be replaced. ATP flex plates are made of high quality steel and contain the correct bolt hole spacing and ring gear teeth just like the original part to ensure long life and durability. ATP part number Z-460 is engineered to replace the original equipment for 1968-1985 GM models.