As
@Rodger mentioned the oil feed reached the alternator, if your current pump fits that's great however, I would be wary of a couple of points.
1st, Does your original pump bearing rely on support from the alternator housing to prevent it being displaced by engine oil pressure within the pump casing?
2nd, Given the oil pressure will be passing from the new alternator to your original pump does the sealing ring mate correctly to both surfaces?
Barring experience gathered whilst working on Rodgers 40 this is pretty new stuff to me, I may simply be being over cautious, I would hate to see you do damage.
Regards
Dave