Suggestions for muscle car sound muffler without drone

I got the 90's and the straight pipes from Jegs or Sumitt to make mine. The 90's were a smooth bend that's one of the reasons I bought prefabed ones. I also used a slip fit on the pipe where it connects to the 90 so there could be some length adjustment/tuning possible. 2" tail pipes with 1.5" resonator. Maximum effect would be a resonator the same diameter as the main pipe but the DB calculation on the resonator looked like it would be enough with the 1.5" pipe and the smaller pipe would be easier to fit in places. The clamped fittings don't look as nice as welded connections but I figured it would be easier to remove the tail pipe if the resonator could be removed.

I would think your Duster would have a similar void where I put mine.