Thinking of swapping mufflers but got a question pertaining to my 340

Hey guys i have a accurate exhaust system on my demon with the performance mufflers. I was thinking of swapping the mufflers out with a pair of gibson mwa mufflers to try and get a little unique tone as i know many people aren't running them. I have one on my single exit bronco exhaust and it sounds good, plus no drone while cruising. My main question is will a high flow muffler hurt me? Gibson says the mwa only flows 3cfm less than.a straight pipe, im running 2 1/4 size duals all the way back. This 340 is pretty stout, dyno was at 400/400 so i know she needs to breathe. Would the high flow muffler hurt my back pressure enough to affect it or will it be better?