73 Wiring harness in a 70??

I have a chance to get a 73 A body wiring harness(underhood) that is in really good shape for a good price. I realize that there will be some extra wires in the 73(seat belt interlock, electronic ignition, a/c etc,) but will it fit otherwise in my 70 Dart. I would like to buy an ez wiring kit but the immediate cash situation for me isn't very good right now.