Just as a first guess, sounds like to much oil in the primary, for the oil leak. The head gasket is another thing altogether. Could be cracked head/cylinder, bad mating surfaces, or clogged oil drain passages.
there is some oil coming out of the gen vent also, but not nearly as much as the trans vent. there is a lot of pressure coming out of the gen vent, seems like too much pressure to me...but then again i dont remember what it was like last fall and i dont now anybody around here with an ironhead to make a comparison...Oil is building up in the lower end....As you said....But if this was the case...You would also be seeing oil coming out the vent at the gen...
I wonder....
On that year model the cam cover has a one way check valve pressed into the cam cover....
My wonder is what would happen if for some reason that would not allow pressure to escape....???
Most likely you can get a loner from Auto-Zone...i do not. where would i come about one?