FLYWHEELS & FLEXPLATES
Find the right part to match your engine from the easy-to-follow guides below. Select flywheels for manual transmission vehicles and flexplates for automatic transmission vehicles. IMPORTANT! All Chevy small-block and big-block engines with one-piece crankshaft seal require an externally balanced flywheel or flexplate. Bolts & Dowels
12337973
Flywheel Bolt (not shown)
• Fits all Chevy small-block V-8, big-block V-8 and 90 V-6 engines
• Sold individually; six required per engine 10046031
Flywheel Dowel (Big-Block) (not shown)
• Highly recommended for all high-performance and competition big-block engines 1453658
Bellhousing Dowel, Clutch Housing/Transmission Dowel (Big-Block) (not shown)
• Use with big-block engine
• Sold individually; two required per engine 3727207
Flexplate Bolt (not shown)
• Fits all Chevy small-block V-8, big-block V-8 and 90 V-6 engines
• Sold individually; six required per engine BIG-BLOCK FLYWHEELS
Part Year of Outside Crank Flange Convertor Starter Ring Technical Notes Number Engine Diameter Bolt Pattern Bolt Pattern Gear Teeth
14085720 1965–89 12.75" 3.58" 10.4" 153 Lightweight nodular iron; weighs approximately 15 lbs. For internally balanced engines.
3963537 1979–90 12.75" 3.58" 10.4" 153 Lightweight nodular iron. Counterweighted for externally balanced 454 engines. Use with balancer P/N 3963530.
3991469 1965–69 14" 3.58" 11" 168 Use with internally balanced engines and balancer P/N 3879623.
3993827 1970–90 14" 3.58" 11" 168 Counterweighted for externally balanced Mark IV 454 engines. Use with balancer P/N 3963530.
14096987 1991–up 14" 3.58" 11" 168 Lightweight nodular iron. For external balanced engines.
12582964 1991–up 14" 3.58" 11.5" 168 Used with 572 crate engine BIG-BLOCK FLEXPLATES
Part Year of Outside Crank Flange Convertor Starter Ring Technical Notes Number Engine Diameter Bolt Pattern Bolt Pattern Gear Teeth
10185034 1991–up 14" 3.58" 10.4" 168 Use with forged steel crank. Has dual-bolt pattern. Only three attaching bolts used with 4L80 transmission.
12561217 1991–up 14" 3.58" 11.75" 168 Use with 572/620 engine and crank P/N 88961554
471597 1965–69 14" 3.58" 11.75" 168 For internally balanced engines
14001992 1970–90 14" 3.58" 11.5" 168 For externally balanced engines | 
