Hey Lisa, whatever you read it's not true!
Nice of Ford to keep the same basic bolting style and shaft diameter on so many alternators for us. The only thing I've seen happen on some pulley swaps is needing to use a small spacer behind the pulley or not. They come with many of the alternators, but you'll have to try your pulley first to make sure it sits on the shaft and does not rub the body of the alternator.
There is a downside to using a v-belt pulley though sometimes. Belt squeal.
Especially in the morning! Luckily you're area is dry enough that you might get less squeal, but it's likely still going to happen. I think there have only been a handful of members here with 3G's that did not get to experience the lovely dulcet tones of a slipping belt on a 3G!
That's why so many of us have gone with a serpentine drive system over the years.
But on a simple Bronco setup without a lot of other accessories another option is dual-groove pulleys. Or a larger diameter pulley too would help.
The Taurus is another common junkyard donor for both the smaller and larger case versions of the 3G. And either size fits the standard Bronco brackets usually. The exception is if your Bronco has the heavy cast steel bracket that originally housed the alternator and the air pump/thermactor setup. Those make the smaller 3G a better choice. Or better still (assuming no air pump) is using the standard triangle upper and curved lower brackets.
There are charts here on the forum in other threads that list the entire older vehicle donor list. Maybe google it using the "site: classicbroncos.com" criteria along with your search terms. Seems to be more robust than the search button here, but either might work for you.
Or, if we're lucky, someone will just post up the list again because they have it saved from previous discussions.
I think both the 95 and the 130 amp versions of the 3G are available in both size cases, but not 100% sure anymore.
The fused wiring harness that I think cali_zuk is referring to is this one:
https://www.wildhorses4x4.com/product/Battery_Charge_Cable_AMG_fused/Bronco_Starters for protecting the main charging circuit.
The fuse blows if the alternator has an internal failure or something short-circuits the cable.
We do also have the fused relay harness for the headlights (https://www.wildhorses4x4.com/product/Night-Lighter-Headlight-Harness/Bronco_Wiring_Harness) since you mentioned it;D
It's not a requirement for protection (the stock headlight switch has it's own circuit-breaker protection) but it's virtually a necessity for getting brighter headlights with a stock wiring harness.
And often still a good thing after a full re-wire with a new harness even.
Hope that all helps.
Paul