[Ford blue blood]

2G was used in 80s/90s Taurus and some other models. They were the first effort to replace the low out first generation alternators Ford used. The wire harness was "cheaped" and under the heavy load of the many gadgets it would burn the harness at the alternator. Ford did a TSB to correct the issue. Nice part is they bolt in where the 1G sat, have an internal regulator and put out good at idle power. They are in the 125 amp range. The upgraded harness for the 2G is readily available.

The 3G is the latest and best, higher output, internal regulator but is physically larger then the 1G and 2G. Care must be taken with sourcing. There are a few models that have the standard 1G mounting. Do a look on Rock Auto, they have good pictures of the alternators.