Man you get after stuff
226F is AC cutoff when the ECU starts trying to "protect" the truck so IMO that is when I start getting really worried - actually I'm with you that once I get over 210-215F I start watching the temps like a hawk. I'm not sure I've ever seen what Toyota says is the max temp when the engine goes boom...
I just had the radiator in my 80 done and it made a huge difference. But it was flow tested before getting done and it was only flowing at like 25%
- Cost wise it was less than $100. Might be worth a call to find out if someone will flow test it for you first before going that route.
Only other things I can think of are making sure you got the t-stat installed correctly and did you test the fan clutch opening temp? Landtank on MUD says they ALL need to be tested before use because they are coming from the factory set wrong...Tool R Us says the ones he has seen have all been fine so take that all for what it is worth. Tools though is the guy that tested the old fan clutches against the new blue hub version and determined the newer blue hub versions aren't as good and sheer the oil quicker, thus the need for the heavier stuff. He also suggests that if you can get your hands on a known good old fan clutch to go with it. I can't remember if the old ones are "serviceable" or not
If you have some time...here is an interesting read over on MUD discussing similar issues to yours with lots of suggestions/opinions