With due respect to Doc, I'm quite certain that you have an M103 engine in your car, as it's not a diesel automobile. The head of an M103 motor is indeed aluminum.
Do a search-M103 Head Gasket issues have been discussed at length. I suggest that you do a full valve job (if not already done), if the head has to come off anyway.
"If everything seems under control, you're simply not going fast enough" --Mario Andretti
1995 E500 street car
1986 Porsche 944 Turbo S track car