You need to re-read his forum entry. Its leaking between the oil cooler base and the block, not between the oil filter and the oil cooler base. I would guess there is an o-ring that is leaking.
The question is HOW is it fixed to the block.
If it is not cast with it, there should be a removal method.
Maybe in the center, with the filter off?
BTW, if if IS a casting leak, Clean the area very clean and dry, and use JB weld quick built up around it.