Simplest way to integrate two Service Manager instances for ticket/information exchange


We are implementing a new Service Manager 9.41 instance to manage a new technology that is being developped in our company. We also have an existing Service Manager 9.31 instance. When we go live, the business will use both. We would like to know what would be a good solution to exchange informaiton between the two SM ? We heard about Propel and its case exchange... but don't seem to be compatible with SM 9.31. Is there any other solutions ?