SCORE on alternator !!

What you list is under 80A. The halogens are most 55w (maybe) at 13.5v is only ~4 a side. Those electric fans have a high inrush start current but still can draw that from the 500A battery. Running is no big deal. The MSD is supposed to take .7-1 amp every 1000 rpm? Pumps are like 5A