The Stovebolt Site Forums The Shop Area General Truck Talk Exhaust manifold crack

I recently removed the intake and exhaust manifold off a 235 I want to put into my 3100 1/2 ton and discovered a crack in the exhaust manifold. I know how good JB Weld is but can it stand up to the temp of an exhaust manifold? If not is there something else that can be recommended?