My corona w/ 22r-e is in at the moment as well, because of overheating, getting a new head gasket and also the head has been sent away to get reshaped/flattened (if its warped, duno if it is yet) in a hot oven, bottom skimmed flat and the cam shaft... made.. circular/flat/no idea.. again.
Cost from $800 to $1500, depending on how sever it is.
Still interested,
What type/model of sony amp is in it? (not that it REALLY matters, just wondering)