Considering 2014 Hemi (5.7) 1971 Demon

Joe Dokes points out the very valid concerns and issues for retroing a later ('09 up 5.7 and '11 up 392) into our old Mopars. The easiest, most simple method would be an '05 down 5.7 truck engine or any 6.1. With that said, certainly the newer engines are the most tempting because they are, well, NEWER and have more hp.

Get in touch with Dave Weber at Modern Mopar Muscle Group who can set you up with a modified OEM ECM and a harness to go with it. If you go this route, I'm pretty sure you can retain the MDS and VVT. I like simple, but this IS pretty cool technology.