Lots of 4wd or SO trucks sit level. Then add weight in the bed and the truck sags.
I pull a 10k car hauler with a 7680 lb blue tractor with the wifes '16 1500 chevy 4wd getting in and out of muddy work sites/pastures. Adds around 1080-1140 lb on the trucks rear axle.
I use a WD hitch/friction bars but found the rear spring pack needed help.
I went with Sumosprings from these guys:
https://www.etrailer.com/susp-2020_Ford_F-150+Raptor.htm They show a 1000 lb or 1500 lb set so give them a 1-800 for their input on what you need. Great bunch to deal with