What oil pan are you running? We used to always run a quart low with stock oil pans on big blocks and Hemis. Because the top quart would ALWAYS disappear. The second quart often would not. I have heard differing opinions as to what was going on. But I have seen many, many times where these engines would lose the top quart of oil when the stock pan was full. And lose it pretty quick, too.

But running a quart low can be dangerous, particularly on a Hemi, so be careful. But it still might be worth a test to see if your major oil consumption is limited to the top quart in the pan or not.