Marc wrote:
I have a 2017 3.5L Ecoboost. Per the door sticker, its payload is 1670 pounds. I have always used a Equalizer hitch
This doesn't tell us anything about your F150 trucks GVWR or its FAWR/RAWR. Especially the truck RAWR as its carrying all the hitch load.
You had much the same questions last fall in another thread and some recommendations.
Trucks payload sticker now days is a gvwr based payload and in many cases if its all used on the trucks rear axle that gvwr based payload can and has overloaded its RAWR numbers.
Looking at your 2017 F150 truck specs on Fleetford.com shows most 3.5 EB engine with a 1670 lb pay;load can be a 3800 RAWR. This is a very soft tear suspension F150.
Other RAWR is the 4050...4550...4800 rawr numbers for a stronger/stiffer rear suspension.
Check your trucks drivers side door post GVWR and RAWR. If its the 3800 I would think in terms of some type of aftermarket rear suspension help/LT C or LT D load tires. Some folks have their rear spring pack re-arched or add another leaf to stiffen the suspension.
Also some tires such as a all terrain/mud terrain with larger lugs and voids can have tread squirm especially carrying a load and a trailer push the truck around in sidewinds or a passing semi truck. Highway tread tires works better....after their broke in if new.