Don't know off hand - but noticed this is in the "Audio & Electronics" section and not a gen specific forum. Is this for an audio system by chance?
If so: Just an FYI - I ran my '99 Tacoma's
70-Amp Alternator on a Rockford T20001BD (2000+ watts RMS) + JL 450/4 (450+ Watts RMS) + Sony XM5026 (100+ Watts RMS) for close to a decade, and never had any alternator/battery issues (replaced the stock alt once in 11+ years). I did use good batteries (Optima, Oddyssey, etc), but that combined with sensible listening habits did the trick. I'm currently at
3600 Watts RMS in my new '13 T4R, and the factory 130-amp alternator is doing just fine. Also had 2000+ Watts RMS in my '87 4Runner, and its factory alternator also held up to the
overall current demands (and I was a young punk back then!

)...
If this is for lights and other "constant draw" ancillary accessories - then you might have more to worry about IMO (butt-loads of auxiliary lights, high duty-cycle winching, etc). But audio systems of multiple-thousand-watts RMS can easily be sustained off the stock Toyota alternator if enjoyed within their non-clipped extremes IMNSHO...
