Agreed. I used Hooker Super Comp headers @ 1-3/4 in my ‘79 Magnum. The current 5.9 project is going in a ‘74 Duster with the standard style 1-5/8 header. I’ve read some headers have an issue with the Magnum motor mount boss. IDK about my case just yet. It’s easily taken care of.
This, I have no idea of. It would take a good search of pictures here to see who did what.