210° @ Cruise and 180° @ Stop? What's Going On?

Of course I run it.

It's what force air through the radiator. Otherwise air just goes around it. Then it add to the pressure behind the radiator reducing the airflow created by the pressure differential.

Does your PRC radiator seal itself all the way around the radiator support. A lot of aftermarket radiators do not. Add closed cell foam to seal that up.

A lot of those "Hot Rod" Spal fan setup just aren't that adequate. They look cool though.

There a guy here on FABO that just added a hood seal and it made a significant difference.