Billet Steel 184-Tooth Flywheel1966-1970 Ford FE 428 SFI Approved 31 lbsExternal Balance HAYS / MR GASKET 12-242 Features:Upgrade your stock flywheel to a Hays SFI-approved billet steel or aluminum flywheel. Each flywheel is precision machined and engineered to handle extreme duty applications along with being designed to take the punishment of today's high horsepower street, off-road, and race engines.SFI-approved � legal for use in racing classes that require SFI certificationChoose precision CNC-machined 1045 billet steel for maximum strength and durability or 6061-T6 billet aluminum construction for weight reduction and excellent heat dissipationAluminum flywheels feature forged heat treated steel ring gears and replaceable 1045 steel.