I have a Paul Turner its a little rough it needs the motor side expansion chamber welded back on. When I got it had the flange welded on so of course it was gonna.break and it did but I have a pipe that could be cut up to fix that if.you know a good welder. I dont have a fat boy to go with it but I do have what I believe is a FMF that was professionally cut and fitted to work with the Paul Turner, I ran.that set up for a good while and it was great.