What are the operating systems on both ends?
a) In the Kernel Configuration Options window, under Advanced Options the ssh command is visible. If you know the option for setting a port try editing the remote command window.
b) Once the remote kernel is launched, it and the front end communicate over two other ports, which cannot be set in advance.
c) Usually, having a firewall between front end and remote kernel dooms a remote kernel connection. You might try a manual remote kernel connection - See the attached notebook.
Attachment: ManualRemoteKernelSteps.nb, URL: ,