Most of our customers are running VisionFlow on port 80, 8080 or 8443 or 443 for https/ssl.
What port should be used can easily be configured in Apache Tomcat, see the file server.xml in Tomcat's conf directory. There you have this entry per default:
<Connector port="8080" protocol="HTTP/1.1"
Here you can change port="8080" to port="80" instead to run Tomcat on port 80.
Please note that you should always make sure the port you want to use is not in use before configuring Tomcat to use it, otherwise Tomcat won't start.
All information about Apache Tomcat configuration is available here http://tomcat.apache.org