70 Dart, how to change regular dash to Rallye dash?

The entire metal dash frame is different for the rallye dash, so the whole thing really needs to come out.

The wiring isn't really that different, you can move some of the wires around in the connectors and make it work. For a '70 you may have to change the connector as well.

I converted the dash frame in my '74, but after doing it that way I wouldn't recommend it. It was a lot of work and rallye dash frames aren't all that difficult to find.