retorque heads to solve issue?

I retorque every time. Stuff moves around. If the OP is running Cometic gaskets that’s what the leak is. Get a mirror on the back of the engine and he will likely see the same thing back there. Any bimetallic engine should have the fasteners retorqued.
I disagree.
Many manufacturers say not to re torque and that it is unnecessary. To each his own.. but let's not serve our own as if it's a widely accepted industry standard.