Any of you 455 guys had trouble with head gaskets? I have a 11:1 455 that has been turning my motor oil milky for two seasons. It usually takes two or three trips for the oil to become bad enough to change. I have always blamed it on the t-valve for my headers but this weekend found a bad head gasket to be the problem. The intake manifold gasket was my second guess but when I pulled it off the gaskets were in perfect shape. The water was coming from one of the water passages right above the second bore (counting front to rear) on the left side. When the motor was rebuilt three years ago the block was decked and the heads milled so the surfaces should be perfect. From the looks of the gasket, water pressure not compression caused it to fail because the gasket pushed in to the bore where the water jacket was. Has anyone had this happen to them? Could the water pressure in the motor cause the head gasket to fail? The hole in the gasket looks like it restricted water flow because it was less than half the size of the entire water jacket. Should I drill or cut a bigger hole in the gasket where the water jackets are? I am thinking about running copper gaskets form Milodon. They say they are reuseable. Any ideas or suggestions?

Im not sure what brand they were. I dont think they were cheapos because the guy that built the motor used all high quality stuff. All ARP faseners, rod bolts, head studs and main studs. I dont think he would cheap out on the gaskets, but you never know unless you do it yourself.