30, 41, 46, 50 amp alternators? Yeah RIGHT

In reference to the early round back alternators, the simplest way to tell exactly what your remanufactured alternator actually is made of is throw the stater on a scale. It's weight would be different.
Once upon a time there was a shop called Mr. Alternator in G'ville SC that would rebuild your unit while you wait. Those variables are the main reason myself and many others would go there (sometimes pull the unit in his parking lot) and wait an hour or two rather than accept whatever the local part store or parts yard had available. His business took off. The "while you wait" thing might have lasted through the first year.