I put old school Thrush glasspacks on mine. Surprisingly, at idle and even pulling out of the driveway type acceleration they aren't much louder than the beer keg muffler I pulled off but lean into it a little and she roars deep and loud. Not all tinny and hollow sounding like the Flowmasters and Magnaflows I had tried in the past and went back to the glasspacks every time. Sorry ya'll, I'm old school.
Back when I was a kid riding around in my dad's trucks or his project car that is all he ever ran... and on a 67 GTO with a 454 they sang a down right pretty song on the highway, so yeah I am hooked.