Full time here. My pickup bed starting at the cab - 50 gallon aux tank, 2 tool boxes designed to hang under a flat bed (but they are well sealed so the lids are on top), Hensley BD-5 trailer saver 5th wheel hitch, then nothing back to the tailgate.
Bought the aux tank and tool boxes at Amazon.
Almost forgot, the bed is an 8 foot bed.
Bill & Linda, 2019 Ram Laramie 3500 dually 4x4 diesel, Hensley BD5 hitch, 2022 Grand Design Solitude 378MBS, 1600 watts solar, Victron 150/100 MPPT controller, GoPower 3kw inverter/charger, 5 SOK 206AH LFP batteries for 1030 ah