Make sure the riser tube from the filter base is still intact. I have seen tractors and Wisconsin engines using this type of filter where the tube has become dislodged from the base and lost... probably thrown away with an old oil filter?
I think the upper end of the riser tube is narrowed down to a small hole to provide built-in restriction to the flow of oil into the filter. Could any of these have been messed with... drilled out, etc., which would cause excess oil to be fed to the filter? Does anyone know what the original size oriface was?