I wouldn't be concerned even at 220, but that is me, I get not wanting to damage anything either, and it continuing to climb is an issue.
I just reread this thread, couple of more things to ponder. I see metal explorer fan, which is as good as it gets IF the clutch is working properly, they do wear out and suffer from the same quality control issues as the rest of our "new" parts, so I wouldn't rule that out. The other is the inner fender screens, they do help, our beloved trucks suffer from tight engine compartments and sometimes they need some help getting air out of the engine bay, I also get not being excited about installing them. I'd save it for last as well.
I will share a heating story that freaked me out and caused a lot of heart burn for nothing. I had an engine that I put TBI on, that I had run for a few months carbed until I got the TBI finished up. it never broke 200. I put the TBI on and the first long grade I pulled the temp jumped to 230, this was with a manual gauge, I panicked shut it down and decided to go back down the grade to town. Parts store was closed, so I ran some screws through the clutch to make it direct drive, made sure it was full of coolant and drove it around some to make sure the tstat was working. Went back up the grade, immediately hit 230 again. pushed on to the top, stayed at 230. The summarization was that the TBI leaned out the mixture and adjusted the timing enough to make the engine make more heat. It never boiled and never exceeded 230 but it always made you think. Sometimes we need to push what we feel are the limits before finding what is too far. The hard part is doing that in a controlled environment that doesn't leave us walking or allow us to push too far and damage something.
PS: I did replace the clutch the next day after the parts store opened.
