I had a 60amp Denso on my Duster, it had a mechanical water pump and fan, electric fuel pump with a return line, worked great, always charged around 14 volts, regular automotive battery.

Now on my 70 Challenger I had a TuffStuff 100amp alternator and an Optima red top battery, I had nothing but battery problems every day, I run an electric water pump, electric fans, and electric fuel pump.
I switched to a regular Walmart battery and life was much better but not perfect. I then bought a 165 Amp Powermaster alternator and now I never charge my battery. It may be way overkill but now all I do is hop in my car and enjoy it every sunny day.