What type of fender wall headers for a 72 duster.

If you tear the fender wells completely out you'll certainly need J tubes or similar. A lot of unnecessary rip and tear in that post 15 picture to use FWs.
IDK if Hookers work with those heads.
Here's the cutout for Hooker FWs..........
https://documents.holley.com/cff26f5b2b70ac5691b75df13d53a72681135106.pdf
You'll likely also need to remove/mod braces from the frame out to the rockers for the collector clearance.

For the street they sit lower making trailering, speed bumps, and such obstacles.