I had Berks HFC's on mine but took them off, too much droning, went back to standard cats and it's perfect imo (DE), lots of pix in my build thread. In summary a great looking and sounding Zorst too. As has already been said no droning with standard cats and sounds great just pootling around or with lots of loud pedal, comes into it's own then. http://www.350z-uk.c.../page__st__120