You cannot rely on a single number found online. Using an incorrect timing setting can severely damage your engine.
The proper way to set the timing is:
1. Consult your owner's manual: This is the most reliable source for the *initial* timing specification for your specific truck. It will likely give a range, rather than a single degree.
2. Use a timing light: This is essential equipment for setting the ignition timing accurately.
3. Find the timing marks: These are usually on the harmonic balancer (damper) at the front of the engine.
4. Set the engine to idle: Let the engine warm up to operating temperature.
5. Connect the timing light: Follow the instructions for your specific timing light.
6. Adjust the distributor: With the timing light illuminating the timing marks, adjust the distributor until the timing is within the specified range in your owner's manual. You'll likely need to loosen the distributor hold-down clamp to do this.
7. Check for vacuum advance: Many distributors have vacuum advance. This should be connected and functioning correctly for optimal performance. The timing will advance further under load.
Instead of looking for a specific number, focus on the procedure above and use your owner's manual as your primary guide. If you don't have the owner's manual, you can often find a digital copy online by searching for "1976 Chevy C10 owner's manual" (or the appropriate model for your truck).
Warning: Incorrect timing can lead to engine damage, poor performance, and increased emissions. If you're uncomfortable performing this task yourself, consult a qualified mechanic.
