I used a plastic drain pipe (ID = 3.25" x L = 3.125") that I bought at Home Depot to act as a support for the fan when the fan hub was being pressed out. Ideally a pipe with an ID slightly greater than 63 millimeters or 2.5 inches would place the support as close as possible to the edges of the fan hub. Some might argue that the outside rim of the fan could be used instead, but I was not willing to put an unnecessary load on an expensive casting. Furthermore, the correct way is to support the