I want to install a high output alternator but an leaning away from the Mustang 3G since it's idle output is ~20A. I read that an '86 Taurus unit was installed using a bracket from a company no longer in business.

Any comments on an alternator that has a high idle output and will drop in a '91 351W?

 

No guarantees, but you might try checking on the alternator from a van of your year and engine. Because a lot of the E-150's saw customizing, with lots of power options, some had some pretty big alternators. For example, my truck came stock with a 65 amp alternator. I was able to purchase a 100 amp unit for an E150 of the same year and engine (302). It should bolt up based on my check of the measurements (though I haven't installed it yet.... engine is being pulled for a rebuild). The alternator is physically larger, but the 65 amp brackets should still allow it to fit. I will have to make some changes to the wire connectors, but that should be it. Hope this helps!

 

yo,
mudman says he got a 130a alt from a diesel truck for his 93:
http://users.superford.org/mudman/

see his home page for an e mail link (hope he doesn't mind)