[65comet]

Ok, my 98 it is the lower intake gasket has gone bad and is leaking coolant into the intake and then flowing into the combustion chamber. But it is a V6. I don't remember the top of a 460, haven't seen one apart in over 30 years. But for that engine I would from what I remember going out on them, think it was a cracked head or block, not a intake gasket problem. But you could be lucky and it is a head gasket gone bad and the leak coming from there. A compression test of the cylinders and coolant system pressure tests would be the first things I'd try. But most likely the heads are going to have to at least come off. Just hope it isn't the block cracked, as that would be your worst case scenario.