Those do not look like the KR/FR500S mufflers.
A lot of people get the KR/FR500S (same thing) mixed up with the Ford Racing Stingers...they are visually different and sound VERY different. I have KR's on my 3v in multiple configurations and they have never once droned. Currently on a car that has all stock exhaust and it sounds just the same inside at cruise now as it did when they were on the other car that had cams/longtubes/offroad mid.
They're very loud and blatty/trumpeting sounding without cats, but it does sound very racecar if you're into that. I got tired of it after a few months.
