The Performance Center server uses port 80 to communicate the Performance Center Administration site and My Performance Center site, and other PC server tasks between the other PC components.
Your ALM server, PC Host (Controllers/Data Processors) , will need port 80 opened bi-directionally, to connect to the PC server(s).
Any Standalone Load Generator or PC Host, designated as only a LG, only needs to connect to the PC Host Controller, on ports 54245 and 54345. However, if any of the PC servers web sites (My Performance Center or even the ALM Desktop Client, is accessed from the LG, it will require port 80 to be open.
You can also look at the following URL, for the latest version, that shows a diagram, with the ports used, that can be useful.
If your company's security guidelines are forcing you to stop using port 80, you will need to configure your entire ALM-PC to use SSL, as detailed in the ALM and Performance Center installation guides, from Micro Focus.