130 amp upgrade alt.
 

We know of all the great benefits of this alt over the 75 amp alternators that come on the fox bodies, but doesn't it also take more power to spin?

Yes, more than likely. But the payoff is WAY worth it, especially at idle. :) Now that you mention it, just free-spinning the pulley by hand takes a lot more effort than an old 65-amp'er. Hmm...now you've got me thinking!!!