What is Distributor cap firing order for 84 ford 1 ton 5.8?

The firing order for a 1984 Ford 1-ton truck with a 5.8L (351 Windsor) engine is 1-5-4-2-6-3-7-8. This is standard for that engine regardless of transmission or other options. However, always double-check your specific engine's markings as there's always a slight chance of variation. You should find this information cast into the engine block itself.