My understanding is the firing order of a 90º V8 compromise between breathing and torsional stress. There are three that are most often used:
• 1-8-4-3-6-5-7-2 (Mopar, Chevy, Ford pre-~'70)
• 1-8-7-3-6-5-4-2 ("4/7 swap")
• 1-8-7-2-6-5-4-3 (Ford ~'70-up, Chev LS)
Regardless of which of these firing orders are used, there will be two cylinders on each bank firing consecutively and once the two cylinders will be adjacent cylinders that fire consecutively.
I hope Old Bogie or Techinspector1 notices this thread and fills in the many blanks/details.