Head gaskets can fail in a myriad of different ways....sometimes it goes one way....and others a different failure mode will be present. The important thing is that you know its a head gasket issue.
Good call on the oil cooler tho guys, I thought of that but you beat me to it....should be easy enough to prove that out tho.....they very RARELY will do this to you however....Oil coolers in the rad seldom fail without trauma of some sort so.....
Dont forget to take the cylinder heads to a machine shop to be spec'd out at THE VERY LEAST.....they will tell you if you need to "cut" the heads back to square again....and YES....it is necessary....there is no other way to properly do a head gasket. Just an FYi