Onservation about magnum 5.9

I don't think the MP folks RE crate engines ever suspected people might use those factory truck and Jeep manifolds in "cars".
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.
Of course they really only work in cars that have manual steering.

I'd be interested to know if that Borgeson steering box clears Magnum manifolds.
This, I have no idea of. It would take a good search of pictures here to see who did what.