Engine running out of fuel

[Duramax66]

This is a crazy one, whenever I fill the tank full I can't run at a steady speed above 60 mph or the truck seems like it is just running out of fuel, when I get to 5/8 tank of fuel everything is fine, so I obviously only fill tank to half full anymore, I have dropped fuel tank and replaced screen on pickup, and changed fuel pump.
This is a 2000 f-350 single cab, cab and chassis with 5 speed manual trans, 4x4.
If anyone has any ideas it would be appreciated.

Thanks