Suggestions for muscle car sound muffler without drone

Recently I was helping a friend work on his set-up (non-Mopar) with a terrible drone. He tried different mufflers without much help. We added an H-Pipe (more to help with the low end torque than the drone) and it did affect the drone slightly. We tried something a bit off the wall. He had two different length Flowmaster 50's, for grins and giggles we threw those on, looks a bit weird but the drone is all but gone!