Low speed stumble, high speed stutter, Bumps make it worse. Options

[eeyore]

My '73 D-Jet w/Pertronix started acting up today. After about 10 miles it began stuttering above 4k RPM rpm on the freeway, so I first I thought it was the same problem as last time, fuel filter and/or pump.

But it never died out, but it did get worse over rough pavement, so I continued on and made it all the way to my friend's shop.

I checked for loose connections on each spark plug wire, the injector connections, the coil, the trigger points on the dizzy, the MPS & CHT wires, and fuel pump connections, and the Vacuum advance hose.

One thing that did seem odd is that when I wiggled the Pertronix I could move it (and the advance plate it is attached to) vertically about an 1/8 inch. That didn't seem right.

Later test drives with moderate throttle reveal a low RPM stumble, like it is too rich, clear running from 2 - 3 kRPM and then more suttering above 3 kRPM. Steady-state throttle was better, but not confidence inspiring enough to drive the car back home.

Help?

Thanks in advance.
Mark