My replacement AC Delco alternator of many years on my 78 Silver Anniversary has developed a rattling sound. My guess is it's on its way out. Does anyone have any experience to share and possible replacement recommendations? Thanks for any help.

You can have it rebuilt, or buy one from a local parts house, or Corvette vendor. ANY reman is a crap shoot, regardless of who rebuilds them. Most of the time they work fine, but sometimes......it might take 3 or 4 before you get one that works. That's why I prefer to rebuild them myself. Just get the parts, and dig in. 🙂