While trying to loosen the flair nut on the egr tube, I found nut seized to the flair fitting that attaches to the exhaust manifold. The tube for the cobra is no longer made. I bought one for a gt and cut the end off of of it and brazed it to the cobra tube. The filler material starts to flow at 1200 degrees. I am having second thoughts now, thinking that I should have used a tig. Does anyone know how hot the egr tube gets at the flair fitting?