position of dash defroster vents

I'm putting together a dash for my 70 Dart, out of the car. I disassembled the dash a few months ago and stripped and painted the dash frame. Now it is time to reassemble!

The pipe on the bottom of the dash defroster vents leans either in toward the firewall or out toward the dash. Which is it????

As an aside, I had a set of new repop defroster vents to use. As I have read here before, they don't really fit and would require significant realigning of the holes in the metal dash frame. This sucks!