I am looking for opinions as to what can cause a head gasket to burn through to the adjacent cylinder right under the head bolt. There was definately no overheating or even a niticable loos in power when it happened. Running WOT for maybe two minutes and when I slowed up ti idle the engine was running on 6 of the eight. No smoke and no water in the oil, just a rough idle. So far I have checked the head bolts (someone I know said they saw this from a cracked head bolt) but all sem OK. Could have been a deffective gasket (I'll never know) or bad torque when the rebuilder assembled it. Any other suggestions and second, do I need to remove the other head?? I hope some of you repair shop guys can let me know what you do when a "V" engine blows a head gasket. Do you always replace them both???