That sounds correct, although you may want to also add this nonstandard HTTP port to the "Application Control Web Browsing Services" on the Manage & Settings...Blades...Application Control & URL Filtering...Advanced screen. I don't believe this additional step would be necessary for proper IPS inspection of HTTP on a nonstandard port, but it may help with some of the other blades.
Also definitely ensure that the "Enable HTTP inspection on non standard ports for Threat Prevention blades" checkbox is set under Manage & Settings...Threat Prevention...Advanced Settings...General...HTTP Inspection and you should be good to go.
Gateway Performance Optimization R81.20 Course
now available at maxpowerfirewalls.com