While I understand the “theory” of moving the pump, I’ve seen a lot of issues with pickups over the years that have had that particular mod done. From poor fuel line connection, to too small of wire and corroded butt connectors. I still run a pump in the stock location. It’s easy to get to and by monitoring my fuel psi I should be able to tell if it gives up the ghost. I’m only on my 2nd lift pump from the oem unit that started weeping after a year of ULSD (Cummins made an upgraded diaphragm).
As far as the theory, I understand it to be the same reason that electric pumps are near the tank on a drag car - electric pumps do better at pushing fuel rather than pulling it. The shorter the straw to start the siphon, the less the pump has to work, the longer it will live. And mine got a 1/2" line from the pump to the filter and from the filter to the VE44 at the time. Mine is on the inner frame rail about 8" in front of the tank. I cut the stock fuel line there, bent it outwards, then plumbed the moved pump to the stock line back into the tank. From the inlet of the pump forward it's all 1/2".
