Is there anything to be gained re torquing Factory Head Bolts? Low milage Motor thats waiting to go in the truck. I thought it could help a bit? Maybe.
if its running fine with no head gasket issues, I would leave it alone!!!
Factory bolts are "torque to yield", meaning they are 1 use only. If you loosen them they must be replaced.
Also steel shim gaskets do not deform like composition gaskets do, so a retourque is not as important in this application.
You could replace your bolts with studs, replacing then 1 at a time. It is pretty easy with the engine out.