Drone can be tough. Same muffler on one engine and exhaust configuration drones but not on another configuation. I had stock pipe configuation with three chambered performance mufflers on the 383 with a cam that had stock lift, twice the overlap, Rhoads lifters and single plane intake with no drone, Then restored car, had engine rebuilt with mild cam close to stock and same exhaust. Then it droned so bad it rattled your brain, hard to talk or do radio. Tried different mufflers and the only one that helped was Dynomax VT but it only decereased the drone 12db. Was better but still not good. Had to install side branch resonators and that worked so you can talk and listen to music. There's a thread here on my journey with the drone titled "Suggestions for muscle car sound muffler without drone".
If you are going to experiment with mufflers I would recommend Dynomax since a number of their models come with 90 day buy back if you are not happy. I tried the turbo ones before the VTs and they bought them back. They even had UPS pick them up. Nice deal since you don't know how you will like a muffler until you try it.
