To be absolutely certain:
1. Check your engine: Look for a casting number on the engine block. This number can help identify the exact specifications.
2. Consult a repair manual: A shop manual specific to your year and engine will have a diagram showing the correct firing order and distributor cap numbering. This is the most reliable method.
3. Look at the distributor cap itself: Some distributor caps have the firing order printed directly on them.
Do not rely solely on a generalized firing order. Incorrectly wired distributor caps can cause serious engine damage.