70 Challenger 440 cr close to 10:1, Lunati Voodoo 60303 cam:
Drone from idle to about 2500 rpm. Almost unbearable low drone.
1-3/4 shorty headers, 3" x-pipe, 16" Dynomax Super Turbo's, 10 or 12 " glass packs along tank, standard rear valance so the pipes bends down about 30 degrees to get outlet under valance.
Rubber hangers, no interferance with body.

Strange thing: When we got the car it had a 512 stroker in it and the same drone, but only between 40 to 60 mph, not from idle. I then added the glass packs and they helped a lot but drone was still there.
After swapping in the milder 440 it got worse than to begin with. It will ring the ears from a low tone at idle and way past 5

All floor pans are covered with Dynomat sound deadener.

The Super Turbo's shouldn't be the worst mufflers. Do the shorty headers play a role? Or the down bends at the outlet? Or is it just a unlucky mismatch of parts?

Any ideas to fix this?