Regards cooling, I've been through a lot with my 2LTE Surf so will share what I know in case it helps. Apologies in advance for the treatise. It's been a journey. I should probably go and talk to someone
When I first ran the truck with an after market temp gauge in, coolant temps would easily hit 110C up a long slow climb (post-turbo EGTs up around 1000F). And that was AFTER I had a 2.5 inch exhaust installed which as I understand it brings EGTs down 100-150F (didn't have probe in before to compare). Also, according to the previous owner the radiator had recently been replaced after he drove into a tree, anyway point is, the truck would get hot as f#%k even in cold weather, not towing or carrying weight and with an improved exhaust. When it started to get hot, I'd run both cabin heaters full blast and that bought me what seemed about 5C of cooling. Possibly enough to avoid catastrophe.
I gave the cooling system a good clean, put new coolant in and then tried servicing the viscous fan clutch myself but had a lot of trouble getting the seal back in correctly, bought a new seal for it but had no luck with that either. It ran out of silicone and stopped working properly which obviously is bad news. The next stupid mistake was trying to drive the truck the short distance home from my mechanic with no fan in (for reasons I won't explain). It over heated so don't ever think you'll get away with that.
Sure enough, a few weeks later the very thing I'd been trying to avoid, happened... the dreaded white smoke

SO... new cylinder head in at great expense. Went after market to save $$$ but engine ran rough as guts on start up so now needs a glow timer. Then tried a new after market fan clutch which ran way too much so returned that under warranty. Finally put a new OEM replacement in. If I were to start over, without doubt, a new genuine fan clutch would be the first thing I'd do. I put a lot of time into trying to sort the original one out myself, and still screwed it up. Obviously that's where all your cooling starts so IMO if there's one thing you 100% want solid, it's the fan.
Around that time I put in a new, cheap Chinese alloy radiator (Redline, claimed 30% extra cooling), replaced the water pump, and ran Toyota red coolant with Redline Water Wetter. That brought max temps down from 110C+ to about 95C so probably safe and acceptable.
A couple of years later the cheap alloy rad sprang a slow leak so I bit the bullet and bought a locally made custom alloy one (A1 Auto Cooling, Chch) on grounds of reliability. Cost $1300NZD but the thing is AWESOME. I run an 82C Tridon high flow thermostat and I haven't seen anything above 85C even with prolonged running of EGTS at 1000F. Basically, it just doesn't get hot any more.
To sum up, the stock cooling in these trucks is completely abysmal so no wonder they're renowned for cracking heads. Seriously, what were Toyota thinking? Did they not bother with testing? In the words of my mechanic "Brand new from factory, tow up a hill and they'd overheat. That's how bad they are".
Good news is, even without an intercooler, it IS possible to get your cooling solid as. Clean cooling system, new fan clutch, new pump, quality extra thick alloy radiator, high flow thermostat, Toyota Red, Water Wetter = happy days. You've got new head, so at least you're starting fresh!