THis must be catching,,,,My brand new 493 stroker leaked like it had been shot from the rear seal,My set up is a brand new Eagle crank ,,,BCR ali main caps with the MP performance billet rear seal...Done the usual fixes no joy ...Found that Mancini,s do a rear main bearing that has a groove to take pressure away from rear seal ,,,,, Changed it from underneath ,,,bit fiddley but i have had a bit of practice ....Problem i think is solved,,,test will be at the track ,,,,Hope this helps