When did they start making 153 tooth flywheels?

All flywheels from 1955-1961 are of the larger 168 tooth style. Starting in 1962, a new flywheel size was introduced: 153 tooth. 153 tooth flywheels may be drilled and accept a 8″, 9″, 9-1/2″ or 10-1/2″ clutch disc and pressure plate assembly – depending on what engine they were originally used with.

How many teeth are in a small block flywheel?

Count the gear teeth on the perimeter of the flywheel. The 12.75-inch flywheel has 153 teeth; the 14-inch flywheel has 168 teeth. The only small-block Chevrolet engine that uses the 14-inch, 168-tooth flywheel is the 400 cubic-inch. Look for a counterweight.

Are there flywheels and Flexplates in a Chevy V8?

All Chevy V8 (1962-1985) engines are internally (or neutrally) balanced and flywheels/flexplates interchange between them. The exceptions to this are the 400 CID Small Block and 454 CID Big Block V8’s.

Where are the bolt holes on a Chevy flywheel?

These are the bolt holes found around the center of the flywheel. According to GM Parts Direct, 1955 to 1985 small-block Chevrolet flywheels have a 3.58-inch bolt pattern, whereas 1986 and later flywheels have a 3-inch bolt pattern. Determine the bolt pattern by measuring the distance between the bolt holes.

What kind of flywheels interchange with Chevys?

Chevrolet / GM Big Block V8 engines have the same block pattern. Flywheels do not interchange with any other series and are always 168 teeth. Buick, Olds, Pontiac and Cadillac block patterns (BOPC) are different.

Can a 1986 Chevy engine accept a 1986 flywheel?

In 1986 a crankshaft and flywheel change was made to the improved, once-piece seal design. 1986 and newer Chevy engines will not accept older flywheels due to the different crank flange and bolt pattern. Older bellhousings, however, will work on 1986 and newer engines.