Flywheels and Flexplates
Chevrolet Performance offers both internally and externally balanced flywheels and flexplates. It is critical that you use the correct design for your specific engine application. Engines with one-piece crankshaft seals require externally balanced flywheels or flexplates (except for ZZ427, ZZ572/620, ZZ572/720R and the Anniversary Edition 427). Check the accompanying charts to find the correct parts for specific engine applications.

Big-Block Flywheel
Part Number: 12582964
Engine Year: 1965-present
Outside Diameter: 14"
Crank Flange Bolt Pattern: 3.580"
Clutch Diameter: 11.500"
Starter Ring gear Teeth: 168
Technical Notes: Used with 427 or 572 crate engine. Internally balanced.