Do the newer magnum style thermostats flow enough

It's not a magnum, just the stat is. Motor is fresh, less than 50 miles and I had the exact problem last year with different motor. It is a brand new b cool 22" 2 core down flow rad. It has the larger cores but can't remember the size off hand.
It runs 195 all day long down the highway and heats up in traffic ( clutch fan no shroud ). I know I need a shroud but is what I'm getting at is that I should be running 180 ish down the highway even with no shroud.
Thanks for the replies, keep er coming.
Sorry, no current pics