Just so you know, a 1968 Dart dash frame will not accept a Rally instrument cluster without a fair bit of cutting and reworking. Easier to just use the Barracuda Rally dash in it's entirety (first pic). Darts just had the standard dash (third pic).
Your second pic is a '70 and up Rally dash, which you can't use in a '68 since the ignition switch is no longer in the dash and has been moved to the steering column.
