skydiver

This is a new topic because i need some advise for all the job to replacing the head gasket in my 97. .I have made a joyrnie from Athens to Halkidiki (about 600 km) without problem, then after a fast ride (they day after the journie) the tempeture rise , the smoke from the excaust whose like a smokegrenade and the cooling fluid was out all over the engine, thats all.
I have a good mechanic friend here (without any subaru experience)and can help me. We have found a new head gasket from a Subaru dealer in Thesaloniki and tommorow is the great day to do the replacing job.I am worries about the cam position and the timing belts.
Any advise plz.