This is a recent post on Forums and I thought it was worth posting here as many DIY are doing head gaskets on older vehicles.Some techs think that head bolts on all turbo engine should be replaced I agree with this to an extent. Depending on price, some head bolt sets are spendy, then i would use the old. All stretch to torque should be replaced, check manual if they have one torque then they don’t have to be replaced if they have a torque followed by a series of tightening specs usually in degrees then replace the bolts. There is no spec as to length Sealant should be put on any bolts that enter the cooling system, oil should be used on the remainder, do not over oil so you have oil in the bottom of the threads as this can affect the torque, also all threads should be cleaned and or chased with a bottoming tap. Be sure all coolant is removed from the threads as this can cause a premature failure. On stretch to torque the original torque is often quite low so it doesn’t take much to affect the tightening sequence. You are also going to have to clean the cooling system of the oil residue. Dawn detergent works the best for this and flush and then flush some more and then again and again. I would also change the oil and again at 200 miles, Oil should be changed at 200 miles after any head gasket repair as it is almost impossible to keep a small amount of anti freeze from entering the oil.