For electrics, I dont care if the core is worth more than the one I'm buying. I don't surrender it until I'm sure the new one works. Mostly, I have a stash of alternators for the 528s. The old 90 amp Bosch alternator's main wear troubles are the brush/ voltage regulator. It is a cheap and easy fix Most electrics are good from the factory. A used one you know worked at one time. With a re-man you don't really know until you put it in.
