When the truck gets to temperature on a very long ride it will get heat

 

Only when I drive it for a long time and it actually gets up to temp it'll blow hot

 

If the engine isn't getting up to temperature, the thermostat is stuck open. Period. End of discussion. It's not possible for the engine to stay that cool if coolant isn't circulating.

Think about it - even at idle, there are 50 explosions happening every second inside the engine. If there's no coolant circulating, the engine will overheat.

 

Yep, even if it's new.

 

And it doesn't have to be stuck open very far for the coolant not to heat up. I had a t-stat that was only open about 0.050" and the coolant never even got warm in the winter.