I was wondering if anyone new where I could get a powerful aftermarket alternator for my 1980 Coupe deVille (368)? Just installed in the truck are four Infinity 120.3dvc 12" subwoofers and two Kenwood KAC-X810D amps (1600 watts max power each, ~750 RMS). It bumps nice as is, but man...

If I turn it up at night, the power drain (~74 amps from a 100 amp alternator...dangerous)almost shuts off my headlights! After doing the math, I figure I need at least 180-190 amps to draw off of. Anyone know where to get performance alternators in that range?

Thats a lot of power... you might try looking at Powermaster (http://www.powermastermotorsports.com/) and seeing if they have what you need.

dual bateries will even out the load put less strain on the alternator.

Thats still a huuge amount of power, if your going to be putting it all to use, might I also suggest poking around a few junkyards to find a diesel version of your car, and grabbing the second battery tray. Wire them in parallell, and redo all the important grounds (if not done already). Im also figuring you added some cushion in there too with your figure. Powermaster has 200 amp units that look like they would fit your needs well, and you can get them in chrome to boot!