If you are ever looking for a particular replacement pigtail connector for a wiring harness on a GM product, this page might help you to at least identify what you have.
http://www.acdelcotechconnect.com/pi...s/gm/pigtails/
Good luck keeping from going cross-eyed looking through them, however.
You do have to wonder, though, WHY in the hell not just standardize the connectors to make life simple?