Or at least trying to avoid it when drilling the oil ways.
I have a late Mexican AS41 case and was ready to drill the oilways. However when I got a drill as far as the rear bearing and checked for run out I discovered that it runs out 5mm along the length of the cam and would certainly break out.
The only solution I can see would be to drill at an angle from the bearing oil groove. Playing with angles on the bench this looks like it might just be possible.
I can’t see why this wouldn’t work - has anyone else tried it?