To retorque or not to retorque? That is the question.

I have worked as an ASE certified dealership mechanic since the 1970's. At that time the "factory" required a cylinder head retorque at 1000 miles. Since then I have noticed ALL cylinder heads can benefit from a retorque; regardless aluminum or cast iron, and regardless of "permatorque" gaskets or not.
During the initial engine build, I tighten the head bolts down in 10-15 ft lb increments, then after reaching full torque go back thru them one by one...loosen and retighten to full torque...the point is the bolts are tightened evenly.
And even then during a retorque check some bolts, typically the short ones, will be "loose" as the shortness seems to not give the bolt as much "stretch" as the long bolts.
I don't wait for 1000 miles any more. The "day after" the engine is first run to break in the cam etc, then either the next day or whenever convenient I retorque the bolts on a COLD engine. Remember the engine was initially torqued and assembled "cold" and therefore the retorque is "cold" also.