5.2 magnum 392 stroker in 70 duster, some ?s and what heads?

What level of performance are you looking for? What are you doing with the car?

Driver/hotrods can use the iron heads mentioned above very well.
Aluminum heads can be anything really. Just feed the drive train oil via the pushrods and all will be good. Edelbrock RPM's, any W series MoPar head....
Totally killer set ups!
Just make sure the lifters feed the hollow pushrods to feed the same oil pushrod feed set of rockers.

Yes in the flywheel
I also beileve yes to the oil pan
Yes on the headers though there will be a slight port misalignment. The port shape changed through out the years but it'll be OK.
OE lifters? Dealer, Summit, Jegs though maybe not in that order... LOL!