alternator 65 amp vs 75 amp will they both fit??

[ManiacMotorsports]

Basically wondering if you can put a 75 amp alternator in a manual transmission car. Says on all the parts store websites that the 65 amp is for a manual trans car and the 75 amp is for an auto, but I don't see why there would be any reason that they wouldn't be interchangable, ie easy upgrade if your changing the alternator anyway.

Thanks-
Travis