You don't need a whole car. As mentioned above in another post, call Hotwire Auto, and they will tell you what you need to run a 6.1 or 6.4 in an old vehicle. Ditch the Nag1 idea, and find a 545RFE out of a 2wd truck or Durango. It's a 5 spd automatic with a slip yoke tail housing, and Hotwire sells a harness to run it and the motor.. Ask Hotwire if they can make a harness to run one of the 8 speed automatics, and control it. If they can, I would go with that! Good luck to you.