My truck has no balls!!!

Measure the volume of fuel delivered during a specified interval of time. From what I see, maybe about 200-350 ml in 10 secconds.

About 30 ml is a fluid ounce.

"mL"?!?....really??? Damn that President Ford

Metric, FTW
though there are some things that always sound better in inches lol

:imo: I have had to go up quite a few of them wound out in 2nd gear.

I did have an issue about a month ago, truck was running fine, seemed like it had normal power, but when I got to around Mt. Airy, it would start climbing fine, but after about 30 seconds with the pedal nearly to the floor it would suddenly lose all power. My assumption was it was starving for fuel after being wide open. I changed the fuel filter and the problem went away. If that wouldn't have worked I would have worked my way to the fuel pump, float, etc.

I have to downshift from 5th to 4th on the Interstate sometimes in the mountains. Going to a different location like Payson or Show Low, I'd likely have to drop down to 3rd, depending on if semis or RVs cause me to have to slow down.

I feel stupid for saying this, but have you checked your compression?