ive never noticed them backing out. had them on over a year now sure i would have noticed something by now. put some thread lock on it if your that worried about it.
your biggest problem is going to be getting the Y pipe to seal. the clamps that came from pacesetter SUCK! get one like this and put a little rtv on it to make sure it seals up good.
http://www.paraballistic.com/images/...bc30_small.jpg
you will also need those clamps for strenth to hold the exhaust together. the first time i steped on it my Y pipe flew off from flexing from torque and the pacesetter clamps were not big enought to hold it on. those clamps that i showed will work good.
