[cwcarpenter98]

I know you just did an initial mock up, but I'm with MT65 on this one. If it ends up hanging that far below the frame rail, that's definitely not ideal.

On the squarebody, part of the tank was under the seat, the rest of it was under the bed. Of course, the floor was stamped to have clearance for that setup.

This idea would require a good bit of metal work, but I've thought about cutting up the rear wall of the cab to be more like the squarebody cab shape. That would allow the tank to sit up higher and be more protected by the surrounding sheet metal.

I also don't want to lose my spare tire under the bed. I also want to take the tank out of the cab at some point. The trailing arm rear end definitely makes that more of a challenge since it doesn't allow space for a tank between the inside frame rail and driveshaft. If your truck is a leaf spring rig, that's something that could be an option