Hays steel flywheels are manufactured from certified billet material that will not break up under the stress of high RPM and severe punishment of racing. This 30 pound flywheel fits the 1986 to 1993 Small Block Chevy 283-400 CID with 1 piece rear main seal and has 153 tooth ring gear. The flywheel is drilled for 10.5 in Borg & Beck or diaphragm style pressure plate. External engine balance. Other weights and applications available.