Suggestions for muscle car sound muffler without drone

So I installed the Magnaflow muffers and it stills drones. Actually louder and really bad. I don't know if there is enough room to add resonance pipes. There isn't a lot of room under a Dart. I checked and it looks like you could add resonance pipes on the sides of the front pipes just before the muffler.

I don't have a H or X pipe. Do these have any effect on drone. Seems like it would change the resonance if you added an X or H pipe. Guess the H would be easier to add than an X.

I'm currently leaning towards Dynamax super turbo's to replace the new Magnaflows to quiet things down. Seems like mufflers can unfortuantly be trial and error sometimes.