351W stroked to 408, overheating

[Abysmal]

OK.
Did a little checking last night and this is what I found.

#1.
The water pump does rotate in a counter clockwise direction as the serpentine belt crosses the pully.

#2.
There is STRONG air moving from the back of the Fan Shroud onto the engine at Idle. SO I am gussing the fan clutch is either shot or just fully locked up. But it is sucking ALOT of air across the radiator and onto the engine.

#3.
Radiator measures..
33.5 inches wide, with the core fins being 28.0 inches wide
Depth = 2.75 on the fins
Height = 18 inches on the fins.

#4.
When cold, there was NO movement of any fluid in the radiator.

#5.
At about 165 degrees the radiator fluid was moving across the top of the radiator from the passenger side to the driver's side. The radiator connections are Top on the passenger side and bottom on the driver side.

#6.
Radiator has a 12lb cap on it with the little red pressure release handle.

#7.
Radiator was LOW on fluid, I added in 48oz of distilled water when the engine was at 180 degrees to bring the fluid level into the throat of the full neck. The overflow container was bone dry.

#8.
This morning when I started the engine, the Air/Fuel meter read VERY LEAN/RED. Rand the kids to school and back. Started the engine a 2nd time, Air/Fuel meter meter Slightly Lean/Red. Went to the gas station and filled up. Started the engine for the 3rd time and the Air/Fuel meter read Normal/Yellow.

#9.
From a COLD start last night, I ran the truck up a long hill in 1st gear to warm up the engine to check the radiator. At the top of the hill I had a water temp of about 125 and an oil temp of 225. Letting the truck sit and idle in my driveway last night both the water & Oil temp leveled out at 180 and stayed there.

[HighPlainsDrifter]

Hi,
Sounds like you had an 'air lock' in the block somewhere or are using a small amount of water if it was down. The air lock will definately cause overheating going down the road. I would suggest putting in a little prestone rad seal [ small round tube of sealer granuals] and change your cap to a 16 lb cap and fill the over flow bottle 1/2 way to make sure water is being sucked back into the engine when cooling and not air. the 16 lb cap will keep more pressure in the block and is not as easy to have air locks. Also will raise the point where water is pushed out into the overflow bottle, as more heavy duty use go up the more cap pressure you need.Race cars such as oval track cars would use a 21 lb cap. If your fan clutch is not working properly I would change it out !!!!! It may just be seizing at idle and when higher RPM's or load put on ,it may free wheel and have no air movement, THIS IS probably your MAIN trouble.
Good luck,
Perry.