On a much more positive not, you could be lucky as I was.

Well it wasn't entirely luck.

First, every day for two weeks, I squirted penetrating oil on each and ever
exhaust stud (8 of them).
Second, we removed the engine and worked on the floor.
Third, I had Frank Condelli at the controls.

He cut away the exhaust flanges. He used vise grips and heat and some muttering.
He removed each and every stud without a whimper. Amazed even Frank. But not me.
I didn't know any better. I used the penetrating oil.
Larry