you are sure it is antifreeze not just moisture , second on a small block the end studs go into water so it could be leaking from the stud into the exhaust header / manifold , it is also possible the AF is leaking into the cylinder from the head gasket but it should be exiting as steam if it was possible to detect at all , last possibilty is a crack in the head beside the exhaust port .
As Oldschool said borrow a pressure tester