I wish I had more progress to report. There is a car show this weekend, and it was another deadline that wasn't met....
I did end up with a Jeep Grand Cherokee fan that's a true dual wind motor for two speeds. MOPAR part number 52079528AD or Dorman part number 620-041. I saw a couple of single speed fans that fit into the factory shroud. For now Ill probably use the existing shroud but It would be too hard to make a custom bracket out of aluminum to replace the plastic one....
