Hi Sean,
The Exhibit and Forefront theme come with this feature.
Here’s the CSS from your first site:
.separate-containers .post-image, .separate-containers .inside-article .page-header-image-single, .separate-containers .inside-article .page-header-image, .separate-containers .inside-article .page-header-content-single, .no-sidebar .inside-article .page-header-image-single, .no-sidebar .inside-article .page-header-image, article .inside-article .page-header-post-image {
margin: -10px -10px 10px;
}
So add that to your new site, and adjust the 10px to whatever your content padding is π