I use 3" pipe all the way back with Dyno Max Turbos and 24" long 3" diameter glass packs in the straight portion of the tailpipes and it's very quiet in the car, no drone. The car actually runs quicker at the track through the exhaust system than with open headers, Saves a lot of mucking around when I arrive at the track. Just put the slicks on and go.
I do lots of highway miles and barely hear the exhaust noise at all, just the nice deep burble all Mopars have.

451" w/ 6 pack.