Old cast aluminum deep pan capacity

Anyone have an idea what the capacity is for this 727 pan? I recently installed it and am having difficulty with achieving the correct fluid level. Also a couple pictures of my first trip out this spring here in Alaska. 34315F8C-DBE6-4437-803D-263A9D908184.jpeg05F84E54-3228-4A26-B587-FC416F50B959.jpeg 81C96CAA-E0C7-4E88-A036-1CF02FD9B160.jpeg