The 4420 lbs., is that your truck by itself? Or is it loaded with people and gear for a trip? If that is curb weight of the empty truck, your actual total payload capacity is 480 lbs.
Thats me in the truck and a full tank of gas..
That payload is if you go by GVWR or my 4900 lb rating..
I do not go by this.. I go by tires and axle weights. My axle rates are 2700 lbs.. ( My tires are above any rating of that truck..)
DOT and comercial drivers use axle and tire weights.. I follow that rule as I drove comercial trucks for a living...
2700x2=5400 lbs..
And you see I restored my front axle to original weight with truck alone.. This is a properly set up WD hitch..
Even thogh my TW is at 9% and not the 10-15% recommended.. My spring pack is the weak link in my set up, as well as the transmission..