Lots of variables in exhaust tone. Compression of the motor has alot to do with how much "bark" you get. More compresion the harder the bark will be at each cylinder pulse. Another is the size of the pipe and thickness of the pipe as well. Ever look at a flowmaster setup? thick wall pipe and a very heavy wall muffler. Sound echos down the pipe more. All of these things can be played with to sdjust the tone you want. A glass pack on an 8:1 305 is going to sound flat like a truck exhaust with a rust hole. Same muffler on an 11:1 355 is going to be loud and bark hard. Just my $.02