MitchF150 wrote:
To get that high tow rating on an F150, you have to have the HDPP and those are not on the used car lots. You might find a MaxTow equipped one and that's better, in that you get a bit more GVWR on the truck, but forget about towing an RV of that 'tow rating' size..
I have a 13 F150 MaxTow Eco with #7700 GVWR and I'm towing a #7000 loaded TT and that's about all I want to tow comfortably with it. It can tow more, has tons of power, but just for the shear comfort level of towing, it's all I want to tow with it.
You will run out of payload long before you reach any 'tow rating'.. So, choose wisely.. The newer Fords all have the auto engine start/stop feature.. No cylinder deactivation, and you can turn off the start/stop, but have to do that every time you start the truck..
To get the old 6.2l in an F150 you have to get the Raptor or a Platinum or higher trim level probably some 5+ years ago.. But, they don't have any payload left, so won't do you any good anyway..
Good luck! Mitch

According to Fords F150 Fleet Guide for 2020 you only need 20" tires, 3.55 gears and the Max Tow to get the 13,200 tow rating. You do need the Super Crew and only 2wd.
https://www.fleet.ford.com/content/dam/aem_fleet/en_us/fleet/towing-guides/2020_Ford_RVandTrailerTowingGuide.pdf