Which alternator 60A or 46A?

is in need of an alternator.
Do you know what's wrong with it?

And let me add here that in most cases you're best off not trading it in as a core.
So if you need to do a quick swap, fine. But odds are the new one will have a crappy wrong pulley, and be missing the internal grease shield.

Bigger is not always better, especially when the battery is run down. Assuming thats the situation now since you say a new alternator is needed, put the battery on a charger.