273 Hi-Po exhaust resonator?

The muffler was a straight through design. You could even look through it and there were only holes in the pipe that passed through making the muffler really only a big resonator. The resonator tip is basically an echo chamber that somewhat mellows the sound at idle, but again it is a straight through design as well. Both muffler and resonator amount to the quietening of a flowmaster 40 or so. They have a nice throaty rumble. the 273 sounded much more menacing than motors much bigger.