Headers in my early A body...HELP

I helped a friend install a set of slip fit headers on his car about three years ago. He asked me to help him with it a couple of weeks ago and we had to pull the headers apart and I figured we were going to have to cut them, BUT we had used some ceramic never seize he bought from McMaster Carr when we installed them and they came right apart. The stuff was kind of expensive (about $35.00 for one spray can)but it sure did work in his case. He'll be ordering it again when his car goes back together.