Big Block Hemi in Duster and Hood

I would rethink using that in the Duster. Better served in an early hot rod like your dad intended. IMHO
Get used hood...paint it.
Engine mounts/brackets, trans bracket all that will need to be fabbed. That engine is heavy. What will you use for a transmission? The early ones would have been cast iron, not aluminum.
I have seen it done. in 68-70 B bodies. I am sure there are guys here with first hand knowledge!