Braze C.I. cracked exhaust manifold?

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Okay, I know that a definitive answer will require more info than I currently have (size of the crack, etc.) - I haven't seen the manifold and don't yet have any details, but....in a very general sense, it is possible to braze a crack in a cast iron exhaust manifold and have it maintain its' integrity thru the normal heat/cool cycles?  Are there better options than brazing in this instance??
Reply:Farmers have been doing it for decades. Brazing is a great cast iron repair because the part heats up and cools down slower that just about any other method. Grind a groove where the crack is and braze it full. Make sure its clean and rust free where you are brazing. Remember flux is your friend.Lincolin Power Wave 450, Lincoln Powermig 255, Lincoln Pro Mig 140, Lincoln Squarewave Tig 275, Miller Big 40 G(with Hobart Hefty suitcase), Thermal Arc 95S and Esab PCM875 in an already full machine shop.
Reply:I like to arc weld cast with nickel rod. Brazing works too. I think if you braze that it helps to polish the area where you are gonna braze with a flap disk on a small grinder. I was told that trick a long time ago and the braze does seem to go better on a really smooth surface. If the cast has cracks in it that are not all the way around it also helps to drill a small hole at the end of those cracks so they don't get bigger as you repair it. Then you just weld the hole shut that you drilled.The worst thing I can think of happening is if everything I ever welded instantly became UNWELDED