Hard to say, muffler selection is totally sound preference based in my opinion. Gains from a muffler swap alone are practically nothing.. maybe a few but nothing you'll feel. I've always preferred the sound of Flowmasters on that engine, but that's just me, and I can't recall hearing Flows with an X pipe before. I had the Mac O/R H mid-pipe on mine and loved the sound, but the unburned gas smell just got to me after a while, and I went back to just the flows. Based on other vehicles I've owned that had straight pipes only, I felt a loss of low end torque, noticeable enough that I didn't care for it and switched to something else.. I would avoid that.