Slant 6 manifold studs

Yes they run into water.
Did you replace the studs?
There was a thread a few weeks ago about replacement studs.
Did you see that?
New head I got ( 1975 or newer ) remanufactured head . Did not have studs in it I ordered new studs and used lock tite thread sealant / lots of it . They are all still leaking badly.