Called another shop in the area today and he couldn't believe that the other shop had broken the alt. Said that sounded like BS. He also stated that even though it sounded like it was spinning fast it probably wasn't going anywhere near as fast as it would be on the engine.

In his opinion the first thing he said is that he's had to replace several that the tolerances were off on some of windings and at high rpm they'll short out inside the case. So before I shell out for the March Alt. I'll let them have a look at this. This one actually might not even be 60amp as a rebuilt unit. Either way they'd fix me up with at least an 80amp unit that won't short out etc.

Fingers are crossed.