There are two diff firing orders for SBF's.
Step 1 : Ford cylinder numbering = 1-2-3-4 passenger side, 5-6-7-8 driver side, not to be confused with a chebby or mopar that alternate from side to side as the count increases
Step 2 : Verify which firing order cam is installed, generally referred to as non-HO firing order, or HO/351w firing order