rear main leak

Try installing the seal at the 6 & 12 oclock position. Then slide the seal retainer down over. With it in place drop your bolts in. If they interfere at all with your retainer you'll need to open the that hole on the retainer that is making contact and that is likely what is causing your seal to leak. When you installed your seal at the separating line and bolt your retainer into place it moves and the edges of your seal is now not meeting.

On my 505 I had installed my seal with the ends of the seal at the separating line. On the dyno it dribbled oil like a bugger and made a real mess of my new TTIs. I replaced the seal and installed it as I described at the 6 & 12 position with a slight wipe of Right Stuff on the seal ends. I used right stuff along the sides of the retainer as well and back together. No leaks so far with a full season at the strip. I actually got this method from a member here on FABO, who has used this method for decades. I forget his name though.