That being said, here's a general overview of the process. This is not a complete, step-by-step guide, and should not be used as a substitute for a proper workshop manual specific to your year and model of vehicle. Always refer to a factory service manual for precise specifications and procedures.
Tools You'll Need:
* Timing light: Essential for accurately reading the crankshaft position.
* Socket set and wrenches: Various sizes will be needed for removing and installing components.
* Distributor wrench: For adjusting the distributor.
* Spark plug wires: To reconnect after timing.
* Owner's manual or a repair manual specific to your vehicle: This is crucial for finding the correct specifications for your engine. It will tell you the proper timing degree (BTDC - Before Top Dead Center) for your specific engine.
* Fuel pressure gauge (optional but recommended): To monitor fuel pressure during the process. This can help avoid problems if something isn't working properly.
General Steps (Always consult your manual for specifics):
1. Safety First: Disconnect the negative battery cable before starting any work.
2. Locate the Timing Marks: Find the timing marks on the crankshaft damper (harmonic balancer) and the timing chain cover (or on the camshaft itself if accessible). These marks indicate the Top Dead Center (TDC) of the number one cylinder's piston. Your manual will show you exactly where to find them.
3. Set the Engine to TDC: Rotate the engine using a wrench on the crankshaft bolt until the timing marks align, indicating the number one piston is at TDC on the compression stroke. Make absolutely sure the mark for the compression stroke is used, and not the exhaust stroke.
4. Check the Distributor: Ensure the rotor is pointing towards the number one spark plug wire position.
5. Connect the Timing Light: Hook up the timing light to the number one spark plug wire and to a good ground.
6. Start the Engine: Start the engine and point the timing light at the crankshaft damper.
7. Read the Timing: The timing light will illuminate the timing marks. The illuminated mark should align with the timing degree specified in your vehicle's repair manual. This degree will vary depending on your engine, and potentially on engine load and RPM, so check your manual for the correct value.
8. Adjust the Timing (if necessary): If the timing is off, loosen the distributor hold-down clamp and rotate the distributor until the timing mark aligns with the specified degree. Tighten the clamp securely once the correct timing is achieved.
9. Recheck: After adjustment, re-check the timing with the timing light to ensure it's correct.
10. Reconnect Everything: Reconnect the battery cable and reattach any components you removed.
Important Considerations for Vortec 350s:
* Computer Control: Vortec 350s are often computer-controlled, meaning the timing is managed electronically. Simply adjusting the distributor may not be enough, and could damage the engine's computer system. You might need a scan tool to access and adjust the timing via the computer.
* Roller Lifters: Vortec engines often have roller lifters, requiring a specific break-in procedure which is vital. Incorrect timing during the break in could cause damage.
* Vacuum Advance: The distributor likely has a vacuum advance mechanism. Ensure this is functioning properly, and check the vacuum lines for leaks.
Again, this is a simplified overview. Consult your vehicle's repair manual for the precise steps, specifications, and safety precautions. Incorrect timing can lead to serious engine damage, including bent valves, detonation, or even catastrophic failure. If you're unsure, get professional help.
