If it has a leak into the valley from the head gasket, there will be no cooling system involvement, as the only cooling channels are at each end of the head.
It is quite common for old V8s with the bottom row of head bolts to leak into the valley as the lower studs tend to "jack" the head so that the upper side facing the valley is lifted . When replacing gaskets it is good practice to either delete the bolts completely or only torque them to 20Ft lbs. They are unnecessary and deleted from later engines.
Regards Philip A

