Template page for specific node
You can override every single node with its node id, as per your nid it should work with node--302998.tpl.php then also if its not working just enable debug mode so you can get idea how many template name available. 

To enalbe debug mode open setting.php $conf['theme_debug'] = TRUE;
 refresh page again and press ctrl + U for view source. 
 you will get all the name those are possible with your page.