You want to come back about and inch and a half or two inches from the flange,,,,,, there is a nice flat place there,,,,,,,,, i was worried but it's pretty simple,,,,,,,,,,, drill it,,, then take a penecil sized magnet to pick the shaveing out of the manifold, then tap and repeat the magnet,,,,,, you dont now have to remove the turbo,,,,,,,,,, i didnt and had noe problem,,,,,,,,
Good Luck
Trey