My existing cooling system has a 13' cap and has been running a bit hotter than I'd like here in S. Florida (215-220). Radiator started oozing a bit too from the core, so it's time to replace/upgrade. Just ordered a new aluminum radiator, new hoses and 180 thermostat. I've searched the forum and didn't find anything relating to the proper radiator cap. Service manual says 14-17'. Should I stick with 13' or replace with 16'?