2x Yes, on fan shroud and factory fan and clutch. 

I pulled a 5x8 cargo trailer over 10,000ft passes in 95 degree weather, running the A/C with the factory cooling setup

If you must use an electric fan, use it as an aux pusher in front of the radiator.

Former vehicle planner for GM and Lexus here.  I suspect your problem is with switching to the electric cooling fan.  Too many folks research on the net and find themselves being told "electric fans are awesome" by some 18 year old who did it on his Honda Civic and thinks everyone should. Aftermarket electric fans and the motors that drive them usually/often have less max cooling capacity than the powerful engine driven fan that was replaced.  I have over 12k posts on one forum, 3k on several and have seen this internet phenomenon across the nearly 10 makes I currently own and play with.  Your engine and its cooling system were designed to work together by one of the finest engineering teams in the world, and the Toyota truck is known as the gold standard in harsh desert environments the world over - particularly 3rd world environments where they are grossly overloaded, and there is no such thing as maintenance.  Those folks just fix them when they break.  So your cooling system is easily up to the task.  Put the original fan back on it, with a new thermostatic hub (these age and loose effectiveness), confirm the sensor is not the issue (good advice above), be sure the radiator shroud is on it, and drive the wheels off it.  This applies to anyone here with a stock Toyota Sunrader engine.  Be advised, there are more powerful fan hubs likely available for your truck as Toyota made a variety of these hubs to account for extreme applications such as a 1 ton diesel sold into Africa.  Both of my LandCruisers got the blue hubs (less slippage, more forceful cooling) decades ago when I learned of them, for instance.  Best!

PS - I acknowledge you had some kind of overheat issue that caused you to have all that mechanical work done and I'm skipping over it not out of disrespect, but because the amount of work you had/are having done would have corrected the damage, and now having a functional factory fan/fresh hub with a new radiator and you should be ready to go.  One comment  I allude to above.  Do you have the radiator shroud in place?  Often, a prior owner will damage it, or accidentally leave it off and then choose not to disassemble everything to put it on.  This part is CRITICAL and often missing on vehicles this age.  Is yours on?

clean the throttle plate and adjust the throttle position sensor