Heres the break down of power testing:
1 amp, single 1000ca everstart maxx, 1 Eagle Picher 12a5000, factory alt
4 ohm nominal = 520 watts @ 88% efficiency (voltage fell from 14.3v, to 14.1v)
2 ohm nominal = 960 watts @ 84% efficiency (voltage fell from 14.3v, to 13.7v)
1 ohm nominal = 1635 watts @ 75% efficiency (voltage fell from 14.3v, to 12.8 volts
.5 ohm nominal = 1890 watts @ 71% efficiency (voltage fell from 14.3v, to 12.8v)
.35 ohm nominal = 2245 watts @ 65% efficiency (voltage fell from 14.3v, to 12.8v)
So depending on what his rise is, 1800-1900 watts when wired to .5ohm
And as i said, id easily run them at .5 daily.....not on all factory, but urs seems to be enough for it