So have a few results to post. Yesterday I made an impulsive trip down to Ramah, CO to buy a jet ski. I get on a long stretch of I-70 where there are no cars at all. Outside temps are about 85°, oil temp is about 220°, coolant is 220°, A/C is on. Ran the truck up to about 100-110mph for about 10-15 minutes with the occasional slow down to 80 when I would need to pass a car. Stock tune, seeing about 24psi boost, 950°EGT's, NO TRAILER, and a pretty nasty headwind. Coolant never moved but oil temp did climb quick. Oil temp ran a consistant 235°. Made a full throttle run up this semi-long hill and temps rose up to 241°. And this was with no load! Once off the interstate the temps did drop back down quickly though.
One thing I did notice though. Anything above 71mph my fan would cycle on and off intermittently. I thought this was odd as going that fast I would think there would be more than enough airflow through the radiator, especially unloaded. My fan has been turning on very easily lately even in relatively cool weather with no A/C. I've pulled two radiators out of customer's truck per their request to clean them. I was amazed at how much junk got washed out of those, and these trucks had 100k less miles on them. So I'm debating on pulling mine out and giving everything a good cleaning.