If your redis server is external to your home network, then its port setting won't have any impact, when accessing the server from within your home network.
If your redis server is running inside your home network, and you access it from inside your home network, then its port setting won't have any impact.
In other situations (e.g. accessing a redis server running inside your home network from outside), you may need to open up the redis port on your home network router to provide access. There is no need to set it to port 80. In any case if wanting to run redis with SSL you will need to assign another port as well (see the howto and setup). If you did set redis to port 80/ plus another port, you would probably have to do some reconfiguring of other services that would seek to use port 80 by default.