I have a drone from the exhaust system on my ram van 2001- 5.9. It only does it in third (the most) and (much less) in overdrive at 900-2100 rpm at part throttle, coasting is totally quiet other than road noise. What ideas can you give to change-adapt to my single exhaust system? By the way,new muffler and cat, stock system.
Thanks

Install a resonator in a section of straight pipe - as long as you can fit. Good glasspack will do. You want something with small louvers, not smooth perforations.

I noticed on my wagons that they're much more likely to have drone than my sedans/hardtops, using essentially the same exhaust system; you're basically sitting in a drum. Anything you can do to break up that big chamber - insulation, maybe even a divider being it's a van - will help. Tailpipes and larger/quieter mufflers help, as should the resonator already mentioned.

X3 on an added "resonator" just a long glasspack(s) in the rear tailpipes will take care of it.

Resonator was what I was thinkng too, I'll have to check length for fit, not much pipe back there. Will another short muffler work, or would that be to much back pressure?

No you'd be fine on that

On both my 360 cars (74 Duster360 and 70 Sport Satellite with 360 in it), there is a "drone" at 2000 rpm . . . I can tell the rpm just by that sound ! Lower or higher RPM, no issue . . . . both are dual exhaust with full tailpipes and "h" pipe . . . from same exhaust shop !