Flowmaster Super 40 vs. Original 40

I currently have a nice 2.5 inch true dual system with H-pipe and Flowmaster Original 40's. My 68 Dart GT has a cammed LA 360, Hooker Super Comp headers, etc.... I love the loud exhaust note my Dart produces. But because it resonates into the vehicle, my ears are ringing. I like it, but thinking about my hearing at the same time. Anyone out there using the Super 40's with this kind of set up???? They have the Delta Flow Technology and it won't resonate as much through the vehicle. Iam afraid the Super 40's would quiet down the car a bit because the casing is an inch bigger in diameter. Still want it to have the same loud exhaust note on the outside. Thanks!!!