We run a 13.5:1 aluminum head 468 BBC in a drag hydro, and recently suffered a head gasket failure. We were using Fel-Pro's 1027 head gaskets, and upon disassembly, we realized that the fire ring portion of the gasket has a small area on each cylinder that protrudes into the combustion chamber, but only on the head side. On the #8 cylinder where the main water transfer hole is, the overhang placed the edge of the chamber on the head side outside of the fire ring, which allowed combustion to erode the gasket and make a path to the water port.
So in my shopping for new gaskets, I placed a call to SCE. Their tech informed me that this is a common problem, and is the reason that they do not sell a gasket with a "bore size" of under 4.520, and they suggested that we run this gasket, even though out bore is only 4.310. They said that if you measure the fel-pro gasket in it's widest area, it's 4.550, but the bore opening isn't round. Theirs are 4.520, and are round.
In summary, has anyone else around here suffered a similar failure? I had considered complaining to Fel-Pro, but am not sure if it's worth the effort...
Thanks in advance for your responses!