Alternator upgrade

http://www.madelectrical.com/electricaltech/amp-gauges.shtml

I found this site while researching Alternators.I heard of guys putting on the 1990 throw 1992 Dodge Ram Gas Denso Alternators.The Amp Gauge and wiring will not live with a 90 amp Alternator.The second diagram looks like the way to go to keep from burning the car down.Has any of you put this Alt on?What mods do you need?