I know these aren't what you mentioned, but I have had a pair of Hooker Aerochamber mufflers on my 340 Dart for 10+ years. They are what I consider quiet. 2.5" pipes and muffs, TTI H pipe system and headers.
My favorite muffler to use on the hotter mills I run in the streets.
They are NOT what I’m inquiring about and not nearly the style or sound level even considered.
I like the Dynomax turbos for upgraded kind of engines.
Hooker Aero Chambers for the hot street strip ride.
Hooker Max Flow or the equal for the race car. Screw sound control! Muha ha ha ha ha….