I have a 185 amp in my GV. Not a direct bolt in, but damn close. Got it from, umm, I forgot. Ace Alternator, that's it. The ones who build alts for Premier Power Welders.
I'm dropping off my Sidekick 55amp alt to Axcel in Schenectady, NY on Friday. They are building it to 120amps. Will let you know how it goes, and they do ship.