I still have a wacky tacky

I thought it was my tach that was bad and causing it to dance around but I installed the tach from the '70 and it does the exact same thing. Coil maybe? Dunno

Paul: It is often a poor connection somewhere in the "white " circuit which basically can be anywhere from the points to the tach. Check the little wire inside the distributor for fraying and check where there is a 2 or 3 way connection in the dash harness. Also check your grounds on the gauges and over by the wiper motor. Lots of options including 2 funky tachs, but unlikely.

Paul,

I guess you checked for a good ground connection on the rear side of the dash?

Check that ground fitting at the coil and where it comes off the dizzy. They are usually fairly frayed there too.

Could be the coil, but I would keep looking.

Allright, I'll check more grounds... Thanks