I’ve got my headings set, in the page editor, as HEADING 3 but when I go to preview or publish the page it shows up as HEADING 5. Here’s a link with a side by side. https://drive.google.com/open?id=0BzdMpO13YhHGNXVEbnFFZS1iMHM
This override is possible from the Customizer under Fonts. A font-family can be assigned across all headings and subheadings. However, in the new version of BoldGrid you can edit heading style directly from the page editor.