Good luck with that! I don't think you can get the sill plates on with the carpet folded over that lip. Every carpet I've seen was trimmed off flush with the top of the lip and then held in place by the sill plate.
Until the weather gets bad in the winter, guess where the truckers go then? When the weather gets bad up north the volume of commercial trucks gets insane down here on I-10.
It was either Classic Auto Air or Vintage Air that had vents made specifically for a non A/C dash with the holes cut out, but after reading through this topic I went and checked and neither one has that option now. No idea why it was dropped.
Like most of the other responders, I run Type F fluid in my 727, always have. I also run one of the deep steel pans and have never had an issue with it.