Are all Ford 302 Firing Orders the same?

Yes and No. You can run this firing order (1-5-4-2-6-3-7-8) in both the Standard 302 and the HO version. But the HO version idles better with this firing order. 1-3-7-2-6-5-4-8. The reason for this difference in the STD-vs-HO is all in the camshaft timing, lift, and duration. Cylinders 5 and 4 , and cylinders 3 and 7 fire really close together as matched pairs. When the H.O. version was cooked up, yo will get a rough idle with the standard firing order. Ford engineers worked this out, and found that swapping cylinders 5-4 with 3-7 got rid of this rough idle. No overall performance difference can be felt with either wiring order. But if you have a 302 HO use the modified firing order. Standard 302---1-5-4-2-6-3-7-8 HO Version------1-3-7-2-6-5-4-8