If I purchase a 6.4 for example from a 4-wheel drive Jeep (can't use the trans here), and then buy a 8HP70 auto trans off the web some place. Holley electronics or Mopar Crate computer can control the engine, Sound German can control the trans, I know I need an auto shifter from an 8HP70 trans. I didn't know if there was a need for the vehicle vin the engine came from and/or the engine computer.