Here is the reply I got back from Mechman Alternators. Looks like the real deal and with a 10 year warranty, I like how they operate and their customer service.
OK, that is no problem. We have actually designed an alternator housing that is carved out of a solid chunk of T6061 aluminum that houses cutting edge 6 phase hairpin stator internals. These internal components offer MUCH better output at idle than any other alternator on the market, and can easily survive 100,000+ miles in the harshest conditions. They feature TWO internal rectifiers that are each 3 times the size of the original Delco alternator rectifier. Our units also have 12 giant press fit diodes, as opposed to the 6 tiny diodes your stock alternator has. These features, along with incredibly efficient dual cooling fans, allow the alternator to cool better, and make more power when hot. Billet-Tech units are stable to 20,000 rpm shaft speed, making them far more durable in high-performance racing applications than other aftermarket alternators. The unit is a direct bolt in/plug in replacement for your original alternator, is made in the USA, and comes with a 10 year warranty. This unit will easily maintain 14+ volts at idle, even with all of your accessories running.
300 rpm turn on
500 rpm - 100 amps
800 rpm - 120 amps
1200 rpm - 150 amps
Polished, Chrome, or black anodized aluminum finishes are available at additional cost.
You can see a dyno test video showing the incredible idle output here: http://www.youtube.com/watch?v=p-j3QNVXN6k
You can learn more about these cutting edge units at: www.billetalternator.com