Flowkooler 330-180 is the number of the thermostat not the pump, The divider plate has to be in there for the pump to work. Best with about 10 thou. clearance from the impeller blades. The Flowkooler impellers are machined, not cast like the originals, that may have caused some interference with the plate. The plate can be shaped with a small hammer and a bucking bar to fit correctly. The water will be spinning around and going nowhere without the plate.