Wow, if this is the 2nd head gasket, that pretty says the head is defective. Either it's warped, or there's a scratch in the mating surface. I would not try another head gasket repair (assuming a correct diagnosis) without replacing the head. Good news is re-manufactured heads are under $400 loaded (meaning valves and cams and all that stuff is already installed).
Or, just swap with a wrecking-yard motor. They are cheap since that is such a common motor and failures are rare. If there's any sign of coolant in the oil, this is the way to go because even slight contamination can cause eventual bearing failure.
