No spring in the lower hose and the suction of the water pump can lead to the hose collapsing, especially at high RPM.General, the overheating was present before I switched to the electric fan/shroud combo, the water pump is a new Motorcraft one. The fans are only on or off there isn't high speed, the description states they flow 2300cfm, I'm assuming that's combined? I'm going to change my settings on the Holley to have both fans on at 190 and see if that makes a difference.
What would cause the lower hose to collapse?


