Just Blew 2 Head Gaskets at Once. First Run

Did you paint the heads before you put them on the engine? I blew a pair of gaskets once and I couldn't work out what the problem was, all the outside bolts had lost torque but the inner ones under the rocker cover were fine, it had to be the paint, I had painted the heads before assembly. They torqued up fine to start with but after the engine got some heat in it the paint softened and the bolts lost torque, cleaned up the area under the bolts new gaskets never had another problem.