The firing order for Chevy Big Block V8 engines (396, 406, 427, 454) is the same as the small blocks: 1-8-4-3-6-5-7-2. The firing order for Chevy LS engines (LS1 to LS7) is different than SB or BB V8 engines. It is 1-8-7-2-6-5-4-3....