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

Lots of great ideas and info here... I just installed some 3/4" plumbing pipe insulation on top of the radiator support on my car to see if that helps, as I am having the same issue of higher temps at hwy speeds. Also ordered a lower hose spring.
I have a 4000-4400 stall convertor and I am sure that's not helping! I also have a tranny cooler mounted out front.

Anyways, thanks to all those who contributed! Here's a photo of my make-shift hood seal. It's a perfect fit and a cheap way to test to see if it helps!