For a stock, distributor-equipped 1988 Mustang GT 5.0L HO:
* Initial Timing: Typically set between 10 and 12 degrees BTDC (Before Top Dead Center). This is the base timing when the engine is idling. You'll need a timing light to verify this.
* Total Timing (at higher RPM): This is where it gets more nuanced. The total timing advances as the engine revs higher. A typical range for a fully advanced 1988 GT 5.0L would be in the 34-38 degrees BTDC range at higher RPMs (usually around 3000 RPM). This advance is mechanical and controlled by the distributor's centrifugal weights and vacuum advance.
Important Considerations:
* Vacuum Advance: The vacuum advance mechanism in the distributor further increases timing based on engine load. Disconnecting the vacuum advance will result in lower total timing. It's crucial for proper operation.
* Mechanical Advance: The distributor's centrifugal weights also add to the timing advance as the engine speed increases.
* Modifications: If the engine has any modifications (e.g., camshaft, intake manifold, headers, computer chip), the timing specifications might be different. The recommended settings will depend on those modifications and ideally should be specified by the person or company who made the modifications.
* Wear and Tear: Over time, wear on the distributor components can affect the accuracy of the timing advance.
* Finding the specs: A reliable 1988 Mustang GT repair manual (Haynes, Chilton, or a Ford factory manual) will provide more detailed specifications and procedures for setting the timing correctly. Always consult your specific vehicle's repair manual.
Do not attempt to adjust the timing without the proper tools and knowledge. Incorrect timing can cause serious engine damage. If you're unsure, it's best to take your vehicle to a qualified mechanic.
