SFI rated 153 tooth flex plate for internally balanced Fits Chevy 350 engines. Requires balancing plate for use on 383, 400 and 454. Has 2 1/2" I.D. center hole. Designed to fit standard OEM, aftermarket replacement, and high performance torque converters. SFI 29.1 certified. Forged one-piece steel ring gears. 0.035 in. thicker than stock flexplates. Constructed from cold-rolled chromoly steel. Long lasting zinc plated finish. Make sure you choose the correct flywheel for your application by reading our tech article. Small Block Fits Chevy - How to Choose a Flexplate