Ford 460 alternator output, how much is TOO much?

[Joe Smith]

After several years of less than stellar performance from my 460's alternator,
I had it re-wound to up the output last week. Before, I would typically see
about 12.5 to 13 volts max on my car's voltage meter at highway cruise speeds.

I am now seeeing 15.0 - 16.0 volts at cruise, and sometimes the needle is
buried in the red if my electric fan is turned off. I'm running an Optima gel
cell battery in my car. My question is this, am I harming my system / battery?
Short or "de-winding" my alternator or changing my pully geometry, what can
I do to make a more managable charge rate? For that matter, what is normal
for my alternator.....I'm assuming 14.5 volts is a nominal output.

Thanks in advance for any advice......