Yes port 3074 for local port range but on remote make sure the port range is 0-65535. Otherwise if you connect to an another Xbox using a different port than 3074, that Xbox priority will be set to 128 while all the others using port 3074 will be set to 1.
I have multiple Xbox's in my home and a lot of times, one of my Xbox will be using a random port and not 3074. Next time you are in lobby, pull up your internet sessions and I'll bet you will see one or two Xbox that you connected to using a random port.