Subject says it all. Looks like the bosses are still there. I am a bit hesitant to try it with a hand drill (block is too big to fit in my drill press) but I also don't particularly like the idea of running the oil from over on the intake side.

 

just run it around to the other side. No big deal. Its been done by 100s of miatas. Id rather run it from the other side then risk metal shavings in my oil passage.

 

I would only do this on a bare block that you can 1000% clean before reassembly. The key part will be to get the flat part perpendicular to the threads, so a crush washer will seal properly. Hard to do without everything set up in a mill.

 

I think I have heard of one person on this site that did it, and was successful. However, he did it with a bare block.

 

You should be able to do it if you tap it for NPT, so you don't need a crush washer. Getting a perpendicular and flat surface so that you can use a crush washer is going to be difficult without the right tools though, but is possible.