In order to complete your clustering test
you should also install IHS 7.0 on at least one machine. Add the IHS to WebSphere as WebServer. Generate the plug-in files and then test sample BeenThere WLM (work load management) application that comes bundled with ND version.
You can try to stop one Web/EJB server in a node to see if IHS is still getting response from other & vice-versa.