B&M 20239 Flexplate Upgraded flexplate for high RPM (6000+) and performance applications, ranging from street to extreme duty racing SFI spec 29.1 approved, NHRA and IHRA legal for all classes Dual bolt pattern design features two bolt circles: 10-3/4" and 11-1/2"; starter ring gear tooth count is 168 For externally balanced setups Backed by the manufacturer with a 1 year limited warranty