My head gasket blew between cyl 3-4 on my 99 Ford Escort. It was never overheated, the gasket just let go. It was driven about 10 mi after the gasket blew. When cleaning the old gasket material away on the block I noticed a tiny groove in the block in the space where the gasket blew. It is just enough to feel with a fingernail. I thought it was from gasket material but the more I cleaned it I realized it seems to be a groove in the block itself. The block is cast iron and the head is aluminum. Pictures: http://s29.postimg.org/6bnyjz8l3/image.jpg http://s24.postimg.org/5n22i3tud/image.jpg http://s24.postimg.org/5pqjiomvp/image.jpg Is this anything to be concerned about? I'm hoping to put a rebuild head and new gasket on. I've thought about putting a tiny bit of JB Weld on it or leaving it as is, but I'm not sure how serious it is. Removing the block is a huge job I'm hoping I can avoid. Thanks.