Yes, it will bolt in. Yes, you will need the Dart under dash harness AND oil pressure sending unit (everything else is the same). Seems to be going the wrong direction, though. Everybody likes the Barracuda dash better (at least everybody I know). My son's '67 Dart convertible has a '67 Barracuda dash. Is there a problem with your frame or with the gauge bezel/cluster? I have two spare '67 Barracuda frames. I don't think I could come up with a nice cluster, but I have enough parts to build one that would work.