compression = horsepower query

If it was mine, I'd cut the heads. With the explosion of aluminum heads on the market, iron heads aren't really worth much except to restorers, so there really isn't much demand for them. Just try to sell a set of iron heads today. Mopar performance sells the .019 head gaskets. Your machine shop should be able to cut the intake side of the head so you can still use a standard intake manifold. Go for it. BTW there was an article about 3 years ago in I believe Car Craft where they tested a big block with 8.5:1 to 11:1 compression by stacking copper head gaskets.