Installing Rallye Dash in a '74 duster issues

The dancing needle is mostly due to the old drive cable, But a new one may not eliminate it. The bearing assembly at the signal generator does get loose after these many years, and I tightened mine up a tad when it was apart back in 98.It minimized the dance. I also took the Odo apart and tried to reset it to zero; but I don't recommend that to anyone. It was a big PITA. I got it down to 3002 miles IIRC, and left it there.I don't recall why it was so difficult, only that it was.
I put a wing on mine too. I had a 70 Dart in hi-school with one, and I just always liked the looks of those on the FB Barracudas, so it was on the must-have list.Kindof like the tinted windows; a must-have.