If it ain't broke don't fix it. If you think you need more amp output from your alternator then replace it with the higher output rating within your year. Mine came with an 80amp unit and when the bearings went south I upped to the 100amp version.
If you think you really need more amp output I'd opt to go to a 130/150amp Sequoia alternator before going Mean Green. You'll have to change the plug on the harness side though; they're available from Onur/beno. There's a thread in the 80's section about doing it.
Its a long story involving a welder but I had the 150amp waiting to install...then had to back down to the 100amp 100-Series on my '99 due to a compatibility issue with the avalanche type rectifier on the Sequoia unit as it related to the welder. So I actually didn't get it installed but I'm 99% sure it will work.
Having said all that the original 80amp unit did a great job of keeping 4 big batteries charged on my '99 and my trailer...and no problems with the 100amp unit either.