I killed drone by using two mufflers with their cases welded together to create a 31" beast. It's a 40 series + a 50 series delta flow. It has 8 chambers and quite a few baffles. There is zero resonance in cab @ cruising speed and it is barely noticeable upon acceleration. But when you put the pedal down, this thing Howls and goes tearing *** in the direction pointed.
Now if they could make the VT in various case lengths and inlet/outlet lengths I'd be more inclined to test. Until then I'll wait for a used one to come along!