change default portfolio metaboxed in The7

gistfile1.txt

function dt_change_default_metabox() {

	global $DT_META_BOXES;

	if ( $DT_META_BOXES ) {

		foreach ( $DT_META_BOXES as $key => $DT_META_BOX ) {
			if (key_exists('id',$DT_META_BOX ) && ($DT_META_BOX['id'] === 'dt_page_box-portfolio_post_media_options') )
			{
				$DT_META_BOXES[ $key ]['fields']['0']['std'] = 'before';
				$DT_META_BOXES[ $key ]['fields']['2']['std'] = 'gallery';
			}
		}
	}
}
add_action( 'admin_init', 'dt_change_default_metabox', 30);