It would be an upgrade to a V6 modern Challenger, but modern Hemi Challengers could easily be modified to make more power than even a stout 440 can put out. And to do a swap would need a fuel injection system and ignition system that could be made compatible with the cars electrical system. It would be cool to see someone do it though!

70 Charger R/T SE 472 Hemi 70 Charger R/T convertible 70 Charger R/T V Code Sixpack 69 Charger R/T SE Sunroofcar 68 Charger 383 68 Charger 318 71 Charger R/T 70 Challenger convertible 71 Challenger convertible 71 Cuda 340 09 Challenger R/T Classic