Use this jig to drill out the boss on your naturally aspirated engine block to add an oil drain for a turbo. 
It has been tested on the OM606, but should fit the other OM60X NA engines as long as they have an embossment like the last photo. 
You'll need your own M5 and M18 drill bit, as well as M6 tap. 
You can keep this item, or return it after use for a 50% refund.
Here is a customer video using it:
https://youtu.be/023WdjPqnWc?si=nCWk5CKQptyamlK3