That was the same muffler I ran,,,, a single Dynomax super turbo.
It has mandrel bent tubing,an "S" bend through the muffler,no baffles,ran 2.5" single out to the back of my Camaro & got a ticket for being too loud.
I think I remember about in the old Clifford catalogs,as not to run anything bigger than 2" pipes or it will be really loud because of the 6 cyl inherrant (SP) special/different/auctive,high level of sound.
I have the old catalogs somewhere.
MBHD