Ignition Timing

Ensure engine is warmed up to normal operating temperature, and that air gap in distributor is correct.
Connect timing light to either No. 1 or No. 4 cylinder. Remove distributor vacuum advance line and plug.

Loosen distributor clamping bolts and turn distributor until timing is within specifications.

Fig 1: Ignition Timing Mark Location

Courtesy of GENERAL MOTORS COMPANY

IGNITION TIMING (Degrees BTDC@RPM)

Application

Timing

Federal Man. Trans. ⁽¹⁾

6@800

All Other Models ⁽¹⁾

6@900

⁽¹⁾	Disconnect and plug distributor vacuum hose.