That's the gear drive I have. You'll love the sound, it does not sound like a dying power steering pump(hmmm.. I think I've heard that comment somewhere else in 5.0 magazine on a vortech blower...).
It sounds exactly like a roots type supercharger. As I said before, make sure your car can run the number if it's going to make that sound. Gear drives attract a lot of attention, and nothing would make a chevy guy happier than to say he beat a blown mustang. Do you know what I mean?