I have heard alot about big city thunder and have read several reviews. They sound like a good product and something I would like to try. I run V&H short shots and have never been impressed with the sound from them. I am hoping Big City will the sound qualities of the exhaust. My question is will I need to retune the motor after installation? Or can I just switch out the old baffles and run without the retune? The bike is carburated if that makes a difference.