1970 Duster want to swap Hemi from 05 300c looking for advice.

You need exhaust those will not work, ECU, wiring harness, front sump oil pan, big hole in floor for transmission, may have notch k-member. Fuel pump,
Supliers. Hotwire. Megasquirt, Mopar performance, Mancini racing. Modern muscle (they outsource most of their stuff). TTI HEADERS, I think Jeep srt8 headers will work. I have TTI
Depends on what trans to use. The Nag1 is gonna be more work with the all the wheel sensors it’s lookng for.