Rear Bearing Puller - DIY

[North Coast Cab]

I drew this very basic diagram of the Hme Depot puller. Can someone tell me the dimensionof the rear plate needed to push the bearing out? Does it need to me round?

Thanks, John

[Zeke]

No, it doesn't have to be round. But round will put more even pressure on the bearing keeping it square to the bore.

After the recent criticism of people posting less than a perfect, all inclusive answer, I am reserved here. But, the best of my recollection is that a 3" surface will suffice.