Putting an OBDII system in a different vehicle is a major electronics job. As the Toolman said, it involves the PCM [power control module aka ECM], the body control module, the programmed ignition key and steering column, the air bag module, the antilock brake module, trans control module [before ~ 2003], door lock sensors, and more. And they all have to talk to each other.
I'd put a magnum or LA in it with a carb and manifold set-up, and a 70's ECU distributor in it, and roll. There is an aftermarket shift/lock-up system for the older OD automatics [non electric].
