cast iron repair

I recently obtained a set of factory headers for my 66 Galaxie. One of the flanges was broken on the right side, so I took it to a reputable welder. I had thought he would do the Ni rod repair, but when I picked it up it was brazed. I questioned him about it, he said that he had brazed numerous exhaust manifolds with no trouble. The repair looks good, he trued the mounting surface so it is nice and flat. Is brazing an acceptable repair? Once I get it mounted, if it doesnt show signs of problems, will it remain robust with all the heat cycles it will go through? I'm thinking I'll attach it to a head that is on the bench and see what it does.

Tom