@Timmo, maybe good time to stop proving your theories with mfg data unless you understand it. There's NO 2000lb payload increase on a F250 due to lower gears. Here's where reading comprehension and understanding vehicle classifications comes in. That chart is for 250/350 srw trucks and the 2000lbs more is a F350 vs a F250.
How do I know? Because neither Ford, nor any other mfg ever put out a "3/4 ton" model with greater than 10klb gvw, until just a couple years ago.
Fun fact, they only did that to appease the folks who don't understand the difference (or lack thereof in this case) between DOT class 2 and class 3 vehicles. In reality, the mfgs, in appeasing the weekend warrior weight cops, screwed up the system for anyone who operates commercially and uses 3/4 tons to stay under DOT driver and vehicle requirements that start with class 3 trucks...unless those commercial operators specifically get a, now, "downgraded" 3/4 ton that is <10klb gvwr.