I've got stainless steel valves in my poly - that was another reason why I went looser. I'd read .02" for the stainless.One reason for hot/cold differences for all iron engines is valve material. Many aftermarket valves are made of stainless steel, which has about 1.5 times greater expansion than steel.
And I am going to do what you outlined in post #12 - I'm going to doublecheck the cold right now, and then hopefully do the hot check tomorrow.