Guess I am dating myself but my experience with Hitachi goes back to the 70's and 80's when they were pretty standard on everything that came out of
Japan. We used the Hitachi to convert old
generator systems to alternators because they were dirt simple, internally regulated and probably more indestructible than the Delco.
All the old stuff was frame grounded. Is this an isolated
alternator and it's up to you to bond the negative to the frame?
I would
head back to where you got it or get them on the
phone and let them tell you what's what. That way if something melts in the process you can inform them that you followed their instructions to a t.