reading about the intake problems where the exhaust crossover heat becomes excessive, possibly when one side of the exhaust system has a leak. it seems to be a very common problem (both the exhaust manifold leaks and cracked intakes)

but what are the symptoms of a cracked intake as it develops and progresses? I read Jim Bounds blog post about how the engine runs fine until it gets up to operating temp then it wont take any throttle and just dies when you try to go above idle but is there any indications in drive-ability that it may be cracking before the crack gets this big?