Converting to ralley dash using a non-ralley harness

I'm converting my 71 Dart to a Ralley dash from a donor 70 Dart 340 Swinger. I have both wiring harnesses, but want to use the 71 harness, which is in excellent condition. The 71 harness has 2 inline connectors with 5 wires in each. The 70 harness has the bullet style with only 8 pins filled. Is it just a matter of replacing the same color wire to the same position? And, what about the extra 2 wires that are not present in the bullet connector? Any help will be greatly appreciated!