Muffler Advice

FWIW, After years of running 1 5/8"-1 3/4" TTI step headers with open exhaust and collectors on my race car, I added their 3" exhaust with X-pipe and DynoMax Ultra Flos ending at the rear axle. I picked up between .05 & .10 in ET. This was with lots of record keeping before & after. The only down sides were the extra 60-70 lbs I had to remove from elsewhere in the car to compensate for the exhaust system weight for a fair comparison and it's a little tight when I need to pull the driveshaft or the pumpkin. I kept it on, but may switch to a DynoMax bullet type muffler for weight & clearance. Basically, I felt that the X-pipe helped and the Ultra Flos didn't hurt. I have gotten a lot of compliments on the sound. I don't know if they would be quiet enough for your tastes, at least not at full throttle. But it scared me for a while because I heard things I never heard before!

You may have to do some minor jetting changes with a more efficient exhaust. But each combo is different.