Exhaust Headers 82 Maxim XJ550

Hey all! I had another problem last night that I forgot to post with the blinker issue.

I swapped out the header pipes from the parts bike onto the runner. Everything fit nice and neat and looks really good. However, when I started the bike, I heard a loud ping and then the engine sounded like it was running straight pipes! After examination, I found that the #1 cylinder exhaust stud on the outside had broken off and the pressure that released, sent the nut accross the room. After further examination, I found that that stud showed some weakness in it where it broke. My conclusion is that when I put the new exhaust headers on, the loosening and tightening of the crown nut must have weakened that stud even more so it couldn't take the pressure and popped.

Now, those look like they are cast into the aluminum, is that correct?

 

I believe there studs that thread into the head.
I hate it for you, they can be fun to get out.
Good luck