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

Hello A Body Nation

I'm perplexed...

I have a freshly built motor and transmission that is running hotter at cruise than it does in stop & go traffic. What could this mean?

Quick details:
-Newly built 410 stroker (less than 300 miles)
-Newly rebuilt A727 (TransGo-2 Shift Kit)
-New PRC aluminum radiator
-2x 11" Electric Spal Puller Fans (3010040011) - Attached to aluminum shroud and set on individual relays (Fan #1 @ 180° / Fan #2 @ 195°)
-Mopar 8 Blade Mechanical Water Pump (MOPP5249559)
-Dana 60 3.73 Gear

I understand a new motor takes some time to loosen up but this is kind of weird. Usually cars run hot in stop and go situations and not at cruise. 210° isn't out of the norm but I just don't see how it can run that warm at highway speeds (with fresh air pulling more than the fans) as opposed to traffic where the fans do all the work.

You're feedback is appreciated.
(I can give further part details but I'm really just curious about what could be causing this phenomenon)