well everyone has been telling me i need some sort of insert where the header meets the X pipe on my car to fix the exhaust leak I have......well i was going through BBk's website and came across this statement about exhaust leaks on the drivers side: The piping itself is correct. For whatever reason, some Mustang models leave the factory with a different style header stud on the Driver side, one that has a "shoulder" on it. This shoulder interferes with the flange, not allowing it to come up all the way and seal against the manifold. There are a couple of things that can be done to correct this. Both solutions require the removal of the factory-supplied studs. Once this has been accomplished, you can either A) replace them with a shoulderless-style stud, or B) simply use a nut-and-bolt setup. This should let the flange to come up further unobstructed, allowing the pipe to seal adequately on that side, providing a leak-free fit.

so with that said.......what do i need to do to go about fixing that? not really sure what I need to buy/do