i had the same problem because i had oil in a bolt hole that caused the bolt to hydrolock before it was actually tight giving me an inaccurate torque reading. i retorqued it after the first heat cycle and it torqued down about 1/4 turn more with the same torque wrench at the same 58 ft lbs setting. my head gasket blew out the side right where the bolt was about 100 miles later when prerunning out along some power lines. the bolt was barely finger tight and when i pulled the head that bolt hole had a bunch of oil inside. i remember heavily dipping the bolts in oil prior to installing them but all the oil ended up dripping into the bolt hole before it was threaded in. all the other holes were pretty dry and the bolts were still tight but that one being full of oil was the only thing i could point my fingers at. i put a new gasket on and made sure the holes were oiled but not full of oil and its been 35k miles.