I had flowmaster 44's and compression bendt tubes and manifolds, the drone was pretty bad at about 22-2300 rpm.
I changed to 1 3/4" primary tubes full length headers into pypes SGF-11R 2,5" kit racepro straigth trough mufflers, and there is no drone, very quiet at crusing speeds, i can hear fuellinjectors tapping and rolling noise from tires at sustained low throttle cruising speeds. But they do sound of when you step on it!.