thank you. i moved the plate to the bumper after that pic, attached with silicone after it was bent to shape. i have the mounting hardware if you want it. stainless and copper.
this is in the "68 vehicle mods for better fuel economy ...'
'Grill blocks come in many forms, though most often they are made to be flush with the outside of the bumper for greatest benefit. Simply inserting a piece of cardboard in front of the radiator does not provide the same aerodynamic benefit.'
65+ Vehicle modifications for better fuel economy - EcoModder.com