Here's a new one on me. One of the diesels I just picked up has the bracketry for a 27SI alternator. I knew GMC used them on the motorhomes. I also knew they were used on the pickups with Olds diesels, but I didn't realize they were used on diesel cars as well.

 

What do they look like on the back? What are they 80 to 100 amp output? I assume they disappeared around the introduction of the 12si alternator.