Just a note.......I have replaced all four bolts that came with the catback. All four bolts seemed to come unscrewed and fall out. I ended up putting bolts on with lockwashers rather than just the lock nut. Something to think about when installing the catback. Granted mine was used by Reg prior and could have something to do with the bolts being unscrewed after intial installation. Get em nice and tight. Doubtfull you will be able to brake that grade of bolt very easily. The other otion.......weld it on!!!!