You lured me from the interwebs today looking into doing close to the same setup. Looking at buying a 67-72 dart to put the 3.6 into. At first i wanted a 4bt but the v6 is so light. From what ive seen the vin parts should match and have every computer the car used since they all have to talk to each other. That was tge issue gasmonkey had and had to cave in and add the parts. RoadKill on you tube did the same thing and explain everything with a hellcat charger motor. Looking forward seeing your progress. Hopefully ill have a dart this year!! Have a 72 charger in the works.