Well I'm no longer finding oil in the air filter and there is not even a drop under the the truck anymore. Also the bolts are no longer loosening themselves (which they were doing with blue lock-tight on them) But even based solely on the metallurgical properties, the thermal expansion rate of Aluminum is 13.1 (microinch/(in F*)). But Cast Steel (3% C) has a thermal expansion rate of 7.0 (microinch/(in F*)). (I actually worked out how much extra force was being exerted on the bolts for EC in one of my classes) I can believe that the Cast Steel Valve cover does in fact expand less due to the fact that thermal expansion is almost half that of the aluminum cover. Having set that aside when holding the two covers side by side you can see the significant difference in the baffling between the two. Also the gasket for a '97 is much much beefer and hugs the curves better to create a much better seal.
Having said all of that the point is there is no longer an oil leak coming from my valve cover.