GN1 exhaust stud oil leak

[hemi8]

Has anyone experianced an oil leak thru an exhaust manifold stud? I am guessing an overtightened stud breaks through or cracks the heads causing oil to seep past the stud creating a small stream of oil down the back of the block. This I believe is just with the Champion aluminum head and may even be just the early heads.
Mike
86 GN