Now I'm not looking for a solution here, this is more backing me up on my theory.

So i had been driving around for about an hour, with my radiator blanket still on, the truck has seemed underheated since the start of winter , with the needle barely getting into the normal (I blame the -30*C weather). So i drive home, everything normal, engines making it's usual amount of clangs and bangs, turn off the truck and the damned thing starts smoking, bad. Rad fluid is spilling out from under the hood over the left front wheel, and steaming is due to the exhaust manifolds ( I assume).

Now, what I figure is it was at its boiling point (the rad fluid) but wasn't boiling due to the waterpump still circulating the fluid. Turn off the truck, waterpump stops spinning, rad fluid starts boiling. I could see it in the overfill box next to the windshield washer and was boiling like mad in there. What do you guys think? (other then taking of the rad blanket)

 

Wondering if your thermostat has a problem - formerly stuck open, but for some reason stuck shut?

 

You're loosing pressure somewhere. The coolant system needs to hold pressure in order to function properly. The pressure raises the boiling point of the coolant. Check for any obvious leaks and one that thing that a lot of people overlook...the radiator cap. Make sure your radiator cap is functioning properly.

 

Did you take off the blanket? That is the first step.