With a little bit of css is not difficult, you can see the results here:
http://gpportfolio.artomultiplo.net/blog/
I just added this code in Simple Css plugin
.single-post .inside-article, .blog .inside-article{
padding-top: 0px;
}
.post-image, .page-header-image-single {
margin-left: -40px;
margin-right: -40px;
}
You should adjust the values (-40px) in relation with your “Spacing” values. It should work with and without sidebars.
And that’s it 🙂