Alternator Output?

On the 2003 Disco what is the Alternator output?  Is it 120A at idle or 120A peak?  There's really very little information out there regarding this and it's somewhat difficult to measure with typical test sets.

I'm most likely in need of at least rebuilding my alternator and putting one in thats tougher and has more output would be good since I'm probably stressing the stock one pretty badly as things are.

It is a 120 amp unit as it is marked on the case.
Why do you need a heavier one, I run a winch thru dual Yellow Top's an Engle 45, 3 HID lights and have never even come close to maxing it out.

How is that rated, until I know how it's rated I can't figure out if I need more or not.

OK, someone was able to tell me that it's peak output.  Next I guess I need to find a way to measure output vs RPM to graph it to compare to other units.

It's not just the winch, there are a lot of other accessories plus running things in camp.  If I have to replace the alternator anyway I want to choose one that will deliver the best performance and ensure no underpowering.  Since at idle the output is lower, and when hot the output is up to 25% lower, not knowing how many amps RMS the rest of the vehicle takes to run, it makes it somewhat difficult.  I don't have a meter that'll like having that much current drawn through it.

If you need a hot alternator, buy a Mean Green, http://www.mean-green.com/index.html
By far the strongest one out there.

I've been trying to get in touch with someone there for some time without luck.  Any idea on specs/price or if I need a custom bracket etc?  

The option of using a HO alternator for welding also came up, and considering some of the places I go, that could be a lifesaver.

They are real hard to get in touch with, customer service is not their strong point but the quality is great.

It's not a linear thing. There is a regulator inside the alternator and Alt output is increased as needed. There might be a minimum RPM to achieve peak Amps. Not sure what that is, probably 1800 RPM or so.