I could have sworn somebody on here had a source for custom rebuilt 140 amp vw alts. It was a couple years ago though.
That would be Duane. blkbstedtrck (sp)
you could always cruise down to your friendly junk yard and pick apart a chevy lumina apv/ olds silhouete/pontiac trans sport. Make sure you get the one with A/C, and fan controls in the back (behind the drivers seat on theside)as they have 145 amp alts.
or you could just get a 200 amp chev truck alternator.probably cheaper than a van alt too.
most chevy truck amps are 105 or 140 amp, 200 amp models are for the 3500 and up series. They are pretty darn big.
The early GM alternators (1974-1987ish) with the integral regulator were not so bad, however most of them were only anywhere from 40 - 75 amps excluding some police cars.. I think there were some GM alts that had a stator terminal (same as the W).. These would be the later style that made the scene in the later 80's to the mid 90's.. AKA the really crappy GM alternators. GM alternators have some great low rpm charging characteristics.. I think that's where their downfall came in later years.. Since they did charge so well at idle GM skimped on the output needed and got away without headlights dimming at idle with everything running.. Of course since they skimped on the output (saving those nickels sure helpt them out didn;t it?) they were taxing them rather heavily and they just didn;t hold up.. Coule that with the quality of most remans out there and they get a bad track record..
Been a while so this is off the cuff. The W terminal is connected to one of the 3 stator windings, pre diode I believe.. I think there is something written about this here for VW alts but the same applies to all of them.. Tap into that and boom you got a W terminal on a gm alt..
In actuality Ford already has this on all their alternators, even the ones with integral regulators.. It's the "S" or stator terminal.. In the ford lineup the integral regulator (g2 series) started to make the scene in about 84.. These were availabe up to about 105 amps, but had a crappy plug to feed the battery that was notorius for burning up.. Starting around '92 the G3 hit the scene (can be identified by the internal fan).. These used a standard bolt on power feed to the battery.. These were available from 90 - 140 amps.... The ideal canditate for one of these would be one from a Taurus with teh OHV v6.. They were 130 amp and although they have a larger external diameter they are about the easiest configuation to mount.. I had one on my Benz and that cheap extra power was darn nice!
AFIK Mopar (This includes Post 87 Jeeps) still uses either an external regulator or the ECM to control the alt.. I'm told some very new GM stuff is beginning to do this now too..