Heavy-Duty SFI Flexplate1962-Up Small Block/Big Block Mopar w/TF727No Ring GearInternally BalancedDual Bolt Pattern (10 & 11.125 in.)11.75 in. Diameter x .147 in. Thick6-Bolt Crank PatternChromoly SteelSFI 29.1 Rated JEGS 601085 Heavy-Duty Flexplate for use with Mopar Small Block and Big Block internally-balanced engines is engineered to handle extreme-duty applications and designed to take the punishment of today's high-horsepower engines. This Flexplate is .035 in. thicker than stock and has a 29.1 SFI approval stamped into the face of the plate.