I have owned my 86 GT convertible 5 spd since 1993. Engine temp gauge went from 1/2 to 3/4 on stock temp gauge approximately in 1997 while stuck in traffic with AC running. Fast forward 12 years and 100,000 miles and I am retired. While searching for the cause over that time period I replaced the water pump with an 86 pump from Ford, several new thermostats, tried flushing block more than once, new 3 row griffin aluminum radiator, checked temperature with both a mechanical and electrical gauge, etc, etc, etc. I no longer have the AC installed and all traces of the system were removed years ago. I have no antifreeze leaks, I have read the threads concerning overheating. Engine always runs at 210 degrees unless the ambient temperature is below 50 degrees. Temperatures increase as rpms increase. I have good condition quality hoses and my lower radiator hose has a solid spring running all the way through. Air/fuel mix is correct based on spark plugs and has been reviewed by myself and mechanics. Mechanics have just said to drive it or pay them and they will search for a cause. Engine runs fine other than over time and abuse its lost its hyperactive nature just like its antique owner. Carcomputer will no longer go to WOT. Ambient temperatures were about 90 degrees yesterday, rpms in 2 to 2500 while rowing gears and then while coasting in 5th at about 1700 rpms temp went to 214 and refused to drop back to 210. Today it made a 7 mile trip to Lowe’s and on the return journey and in 80 degree ambient temperature and 1700 rpm it went to 211. Being an 86 I believe the temp should be around 195 unless the engine is being pushed at 2000rpm and up. The sending unit for the electrical temp gauge is mounted in the thermostat housing. The engine is stock, fan housing excellent, clutch fan assembly very good condition. Ford service guy and fox body owner told me years ago that the “head bolts for the “junk” turbo swirl heads”might have stretched slightly” yet I have never found any indication of leaking in the engine or cooling system. One thread said if temp increases at highway speeds it is an airflow issue or water pump. I’m willing to try another water pump but don’t know which one to choose. Getting old and I still haven’t figured this out. You’re thoughts please.