I see this as a legitimate post! I asked the same thing when getting my Lariat ordered, NOBODY could tell me what the CCC would be and I had to figure it out for myself. Mikeinatlanta was very helpful which gave me a breakthrough moment and I was able to determine that the 3.73 gear lost me a couple hundred pounds of payload so I went with the 3.55 gear instead. I studied the weight of options guide (see prior post) to figure what wheels, mirrors, tires, etc, weight was within my weight budget. Heavy options are sunroof, gate step, bed steps, running boards, spray liner, etc... My payload sticker turned out to be 1910lbs on a 2019 Lariat 5.0 4x4 FX4 SCAB which is what I was hoping for so I do not have to remove anything. My previous F150 XL 5.0 4x4 SCAB had 2212lbs on the sticker. I was thinking the exact same thing - PAYLOAD is king. I found that I could save weight by removing the front tow hooks, front valance panel, underhood shields and insulation, floor mats, jack assembly, spare tire, running boards, skid plates, tail gate, rear seat, rear seat belts, polished exhaust tip - this will get the 250lbs he is looking for. Also P tires vs. LT tires will gain about 40lbs payload - I know this does not make sense because the truck is not carrying the tires but the weight of the truck on a scale is what is counted toward the payload sticker.

 

 

This sounds like it would work for you: Roadmaster Active Suspension You wouldn't have to remove it either, but if you wanted to, it's just a bolt on item with no mods.

 

Tear out all the carpeting -- that's a bunch of weight right there

 

I have a set of TIMBREN rears for my 2019. I have used Timbren on prior heavy loaded vehicle and they are AWESOME, inexpensive, easy to install, no maintenance and just plain work! I was still within my weight ratings though. There is no way to change the yellow load sticker to a higher number once the vehicle is built and I understand about wanting to stay within the limits. I do not endorse going over the ratings even though millions of people do. I cannot bring myself to overload in case something happens.... The OP is concerned with staying safe and legal - I applaud that! The legitimate way to do this is exactly what he is doing - remove dead weight to get useable payload. I would suggest also putting the removed jack/spare if needed in the rearmost part of the trailer to offset some tongue weight but not too much to cause it to go off balance. Careful trailer loading will make it a lot better towing experience - keep heavy items down low and light items in the cabinets. Balance as needed right to left and front to rear when travelling. I have a conventional trailer (Casita) with 500lbs tongue weight and it tows without sway until I get full water in the rearmost tank - then I get sway and have to adjust the load. A 5th wheel is not as sensitive to this but still needs consideration. I think the OP is well within his truck capabilities if he knows his weights of what is going in the truck and in the trailer and balances accordingly.

 

Still hard to believe that specing the much stronger 3.73 and 9.75" diff would actually decrease payload, even though it increases tow rating, but in Ford land it's a fact. I opted to say screw the little yellow tag and get the heavier parts. Haven't got LT tires but considering them. Same truck as yours but with 3.73 and 1790 payload.