727 to 5.9 magnum

Go to a hardware store and get one of those hole saws used to cut out the hole for the door handle. It has a drill bit in the middle with a hole saw around it. Drill the hole about 1/4" in from the edge of the 727 bellhousing. That will give you a nice clean cutout for the crank position sensor.

If this was difficult to sort out, who's doing the wiring harness for you?