Temp too high ?

P.S. I just realised you might want to know a little about the engine...
340 6bbl
Solid cam 580 lift ( give or take a few degrees) 10 . 5 comp. Headers.
4 speed with 4.10 rear (489 posi track)
360 4bbl here with alloy heads,; Also a 4speed; but with 3.55s now, (used to run 4.30s. )
First cam; I ran was the [email protected](292/292/108mopar) ~.540lift and and at 11.3Scr
Second cam: I ran a [email protected], .539/.549 lift IIRC, initially also at 11.3, bur reduced to ~10.7Scr
Third and current cam: [email protected]; .549/.571lift, at 11/1
all were FTHs

My system runs at 207*F by IR gun, at the stat house. Once there it doesn't move, thanks to a viscous clutch with a thermostatic control, and a fresh-air intake system.
What would be considered too high which can possibly cause engine problems,
Well they say that oil is usually good to ~240, so
If the pistons or rings don't swell up and lock the engine, I suppose 240 would be the upper limit........ but I wouldn't test it, lol. I run a 7-quart oil pan for a hint of protection.
240 in the oil might not be 240 in the coolant.
My rad is out of a 73Dart 318-A/C car. Even the patches on it have patches. To be fair, I had it boiled-out in 1999........ lol.