Hello:
I put 10.5 into a pan I had on my workbench and it is too full with that amount, period.
The pans are the same for all the Gen III trucks.
Some of the manuals state 10.5 which is wrong as do the specs (like you provided).
There were a few different dipsticks and perhaps yours is shorter than most which would indicate full with 10.5
As mentioned earlier, 10.5 overloads the crank scraper, flings oil onto the cylinders and overloads the oil-rings. That can cause the engine to burn oil.
In the end, it's up to you to do what you think is right.
Cheers.