Additional fuel carrying capacity on pickup

Unsure what truck you have but take a look at Titan fuel tanks. They may offer a midship replacement tank. Based on some info in your post and some assumptions ford, 350, short bed, diesel 2017-2022 they offer a 55 gallon tank that takes the place of your existing fuel tank. No bed space lost or additional plumbing. I have had them in my last couple trucks and worth every penny as far as I am concerned. The new truck I have on order comes with a 50 gallon tank so wont put one it.

I have used Titan but transfer flow, S&B, or Aero tanks may make them as well

https://titanfueltanks.com/products/xxl-replacement-tanks?find=2019-ford-f350-4678&sid=NTAFkrcZnz