I have stripped the threads from the block of the long bolt (upper right) attaching the oil filter housing to the oil pump housing.

I would like to drill that hole out by about 2mm to get a tap for a helicoil down to where the threads were. I am sure that the oil pump housing has all sorts of oil passages and certainly don't want to hit any. Is this a safe thing to do? It seems to be MUCH easier than removing the oil pump housing to get to those threads.

Thanks for any advice.