HI kenikh
you just need to make the No'3 main the same profile as the No'2 main as the photo;
to clear the oil pump case and clearance round the pump, 964 pump in a 7R case;
please do not use a grinder on the mag case, a linisher/belt sander or a diegrinder with a corse cutter, as I have found hard bits in the casting and have been told the Mag'will set on fire easly, it has been known.
regards mike