I just got my 401 back from the machine shop and am getting ready to assemble it.

So far all of the oil bypass writeups I've seen only show pictures, not exact measurements. I'll admit it, I'm timid as hell about drilling into my block. Do I need exact measurements, or is going by the picture and getting the hole "close enough" going to work?

This is the oil bypass going from the front of the block to the lifter oil gallery.

Thanks,
Robert