* The base ignition timing for a 1978 Chevy 350 is typically set at 4 degrees before top dead center (BTDC).
* This setting can vary depending on the model year and engine configuration, so it's best to refer to the owner's manual or service manual for the specific engine's timing specifications.
Adjustment Procedure:
1. Ensure that the engine is at operating temperature.
2. Locate the timing mark on the engine's timing cover or harmonic balancer.
3. Connect a timing light to the engine's ignition system and attach the inductive lead to the No. 1 spark plug wire.
4. Start the engine and allow it to run at idle.
5. Point the timing light at the timing mark and observe the position of the mark in relation to the pointer.
6. If the mark is not aligned with the pointer, loosen the distributor hold-down clamp.
7. Rotate the distributor until the timing mark is aligned with the pointer.
8. Tighten the distributor hold-down clamp.
Note:
* Be sure to disconnect the timing light before starting the engine.
* It is recommended to verify and adjust the ignition timing whenever the distributor cap or rotor is replaced or any work is done on the ignition system.
* If you encounter difficulty adjusting the timing, consult a qualified mechanic for assistance.
