My experience with noise goes like this. A 235 with Fentons, and steel pack mufflers, the shorter the better for more noise (mine were Porters), will yield ear splitting, glass breaking sound if done right. A cop in Burbank told me mine sounded like an airplane taking off (and we were right under the Lockheed airport). I now have Corvair turbo mufflers with Fentons and 2" pipes. The sound is quite subdued but still has the 6 cyl "beat".
