The more I think about this, the more I lean towards this: Winter is approaching, ie: Cobra storage time for us Midwesterners. I would remove the tank,( after THOROUGHLY flushing and rinsing it..) and cut a large, "access" panel from the top, to verify the condition inside. If possible, perhaps modifications could be made to the pickup, and baffles TIGed in to control the fuel movement, and the top piece welded back on. If this seems unfeasable, a custom made fuel cell is probably in order. These remote setups seem somewhat unsafe, and a bit redundant, though they may work. Short of this, I don't see any other safe, effective way to resolve the problem.
But, I'm still thinking....(should be working!
)
Dave