Port 53 is Domain Name System(DNS). In the ACE this is set by either specifying eq 53 or eq domain. Both accomplish the same outcome.  Here are the options available to the eq portion of the ACE: [IMAGE] If this ACE is in the running config, then the L4 port of the ACE will load and be the same as is currently is.  Is there something specific you are wanting to achieve? Or just gathering information? 
Where is the L4 port detail of a ace saved on my 6224? show ip access-list acldom5 show running-config
6224 running-config does not show L4 port of ace