This is the opposite end of the question: "will dual carbs improve the power on my otherwise perfectly stock 235"?
And the answer is basically the same: go back to the post by Hollow55, and reread.
Will probably give you more issues with trying to get a smooth idle. You might gain 5 HP at wide open throttle. How often will you be at wide open throttle???
Since you mentioned the wife is currently unhappy with the noise, and you aren't making any additional engine mods; would suggest going with stock exhaust.
(Opinion) MUCH better to impress the wife that you listened to her concerns than to impress the 15-year-old across the street with the noise!
Jon.
