It's possible, though unlikely, that the cause of a leaking head gasket is simply loose head bolts, it only takes five minutes to check. Torque all bolts in the normal sequence. If any turned, you might have fixed it, but monitor your coolant level, because you might have a stretched bolt or so.
Failing this, I have sometimes fixed a leaking head gasket by tightening the bolts three pounds more than the number in the book (after all, that gasket has been squished for 34 years)
It takes more torque to start it turning than it is set at.