My Cobra could be heard from one and a half miles away.
I changed to the Classic Cobra Pack 3" inside but four inches longer (28"). The old mufflers were 2 3/4' i.s. and 24" long.
They were a "lot" quieter. I could talk to my passenger with out screaming.
Nice healthy rumble.
When I installed them I cut a little off the front pipe and a couple of inches off the rear turn down tip to keep the original over all length. I did turn the tips up to keep the sound from bouncing off the pavement but not so high as to bother the guy next to me at the traffic light.
Worked out great and I love them!
Classic Chambered Exhaust Inc. - Products