Help with Rallye harness replacing standard harness 70 dart

I see where 74 got into this thread at a drawing which is pretty much irelenvant here.
70 model standard/all got ignition switch and hazard switch moved to steering column. The rallye instrument panel from 69 and earlier was carried over into this new generation for 70 and 71. I have no idea what differences might be found in this "hybrid". Harness becomes hardness?
I think changing standard harness connectors to work on rallye panel circuit boards is easier. Change oil sender from warning lamp type to gauge type and done. Well almost. The rallye panel may need a couple of mods, solid state IVR and amp gauge changed to volts gauge.