For most 5.4L Ford V8 engines:
* 1-5-4-2-6-3-7-8
For some older models (pre-2003):
* 1-3-7-2-6-5-4-8
How to determine the correct firing order for your specific engine:
1. Locate the engine block number: This is usually stamped on the engine block near the front.
2. Use the engine block number to look up the correct firing order: You can find this information in a repair manual, online, or by contacting a Ford dealership.
Example: A 2004 Ford F-150 with a 5.4L engine would likely use the firing order 1-5-4-2-6-3-7-8.
Note: It's always best to confirm the firing order for your specific engine model to avoid any issues.