Just to be safe I would check to see if your brakes are dragging due to a stuck caliper causing the engine to work overtime and overheat.
Park the truck on a SLIGHT hill (not much of an angle at all just enough to make a normal car or truck roll backwards), sit inside, put the transmission in neutral let off the parking brake and pedal and see if it rolls. If not, something is dragging probably brakes.
Also not a bad idea to do a real oil pressure check using a manual oil pressure gauge tester. Low oil pressure will send temps up under load.
Did you also verify the engine timing is at correct specs? Could be a worn out timing chain causing timing problems which will also overheat a vehicle.
I would almost bet money it is in your brakes.
Note I said almost.

 

Well I checked my brakes and it rolls freely in neutral... The trailer didn't have trailer brakes...

 

OK, not the brakes.
Hows the catalytic convertor?
A clogged CC can cause over heating.
Also make sure you do not have air in the cooling system.
The reason I am giving so many things to check is in my experience (and I have a lot) it is always something other than you think it is and you spend a lot of time and money fixing things that are not bad.

 

Just thinking, have you checked the cooling fan clutch?
Is the fan blowing like it should?

 

Checked the serpentine belt, is it routed correctly or is it slipping?

 

I appreciate all the ideas.. The more the better cause I know what you mean about fixing things that don't need to be fixed.. The belt is in good shape and routed correctly.. I can't be positive I don't have an air pocket but I'm gonna flush it and do all that as soon as I can this week.. And the fan seems to be good, no play and it has resistance...

 

Flushed the system out and another new thermostat and presure cap and still no luck...

 

reallly.... hmmmmokay so u`ve replaced everything except the water pump correct? if so possible the water pumps fins have rusted up

 

Yeah everything but the fan, water pump and coolant temp sensor... So maybe it is the water pump

 

Not to hijack, but sounds like my problem too. I just bought the truck last weekend, towed the boat Monday about 30 miles and it started to get hot. I thought it was caused by the heat index being 110 and having the A/C blowing full blast and driving 65 that caused it. I hope flushing the rad. will help. Soon as I discoed the trailer and drove around the block the temp went down....