On my engine ('99, 360 v8 Magnum), I replaced the spark plugs less than 15k miles ago, because of misfires in cylinders 2 and 8. Those two plugs were badly corroded. Today I had to replace them again, and the same 2 were far more corroded than the others.
Because I have found evidence of a head gasket leak (burned coolant smell in exhaust and loss of coolant), I was thinking perhaps the coolant was getting into those 2 cylinders and causing faster corrosion. Is that likely? If not, what's causing the rapid deterioration?