It is not necessary to drill the block, the EK mentioned has the line exiting via the side of the sump, however we chose to drill the block as we thought this to be a better option.
In simple terms what needs to be done is to divert the oil from the oil pump through a filter and back into the block. On standard set up, there is a pipe that comes from the pump to the block where it flows into a T, where 1 section goes to the oil switch and the other to the motor. We diverted this flow by routing the pipe out the side of the block, through the filter and back in via the oil switch port. Naturally we blocked off the block at the lower section of the T where the original set up entered.
Here is pics of the EK's setup through the sump. (also has an oil cooler set up)
An FX with an outlet drilled into the block.
Here is our set up.
Regards
Alex