exhaust drone/harmonic resonance

I also put in the sound deadner and bought some 1/4 closed cell foam to put under the seats. All this made a difference but did not eliminate the drone. Dusterglen try to talk out loud when you hear the noise it reminds me of talking into a fan when i was a kid. I also have a 360 in my car but an x pipe. I have a lunati cam, air gap intake and edlebrock carb.