Throwing around a couple dangerous ideas!

An early A body is difficult to install a Gen III Hemi in. You have to have an entirely new front suspension like an HDK or Alterkation, and then you have to replace the inner front fender aprons with flat sheet metal to clear the heads because the new Hemi is so wide. I have been tinkering with a 5.7 Hemi in my 70 Duster, along with a 545RFE trans. I've got an 06 motor with 6K miles on it, but I am out of love with the whole Gen III thing, and will probably put all that stuff up for sale soon and go back to a small block with a 4 speed. Best of luck, and NICE Charger!