rear main leak

Are the two halves of the seal "clocked" just of a little, so that the seal can act as its own aligning portion of what takes place with that bolt on aluminium housing ?
did u use guidance studs to keep it lined up when installing? sometimes it will help. are u running a girdle? if so, u might want to get rid of the part that catches oil in front of the seal , that really does nothing for strength.