accessory holes B1Ba heads

I have a set of B1BA heads on my 360 and need an accessory hole drilled on the driver side head for my procharger bracket. Does anyone have experience with this? How deep can it be drilled?View attachment 1716244359
In the spot your circle is drawn there is 1.4” depth to the intake coolant passage behind it.
The intake manifold bolt blind hole is drilled about 1” depth, so it intersects that area just under your circle. Here is a picture with a mark showing where the bolt hole should end up intersecting. You can see the bolt hole on the intake face there on the left.
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