Another "Hot" problem

Many posts. My rough summary from reading others woes is:

Changing the thermostat won't help, since once full-open it doesn't affect it. A 195 F will give better mileage, w/o causing over-heating. Avoid "fail-safe" ones since they lock open if ever overheated, then your car will run cold in the winter.

Best way to verify your dash gage is to watch it in the winter. Once heated, if it holds a steady position, that mark should correspond to your T-stat setting, so any numerical marks on your gage should "calibrate" to that. This assumes you know your T-stat opens at the stamped mark (tested in hot pot w/ thermometer).

Most who installed a new aluminum radiator had their cooling issues disappear. Don't recall results for a new copper radiator, but as post #2 says, even if an old radiator flows fine, the fins may have detached from the tubes on the outside.

Shrouds and sealing the radiator to hood helps a lot.

A larger area radiator helps. You don't need to cut the opening larger to get most of the benefit.

More rows doesn't always help, especially w/ new aluminum radiators.