Towing with our truck- what too heavy

As a F150/SC/5.4/SB owner, use the sticker on the door, the manual has a table and you would need to know all of the configurations of your truck. A trailer package is unique to the model/year but often comes with a 7-pin elect connection on the rear, a 2" receiver hitch, a transmission cooler, electrical pre-wire for trailer brake controller, maybe more but not tow more. A weight distribution hitch will allow you to tow a heavier tongue weight trailer BETTER as it transfers some of the weight to the front axle (better handling/steering/braking. However, you hitch will be stamped with two weights; using a drawbar (probably 500lb) and a wdh (Probably 1,000 or 1200). Without a wdh, you bumper will drop several inches when you hitch up. My trucks listed stats are:
UVW 5871
Avail Cargo/Hitch 1329
GVWR 7200
GCWR 14500
Gear 3.73
FGAWR 3750
RGAWR 3850
MAX TT 8700

My Rockwood 2902SS was listed as:
GVWR 7598
UVW 5432
Hitch 614
CCC 1833

However...TT loaded with pot/pans/clothes for 3-pax-4days/propane; 1/4 fresh water, no passengers, two bins in the bed I weighed in at:

Steer 3140
Drive 3960
TT 6040
CGW 13140

With a wdh and dual cam sway controll I never had a towing problem even with big rigs, high winds, etc. However, if the fresh water tank was empty and I loaded the rear bunk with gear I did get sway. loaded the TT forward of the axle and I was fine.

Just my data to hopefully educate you.