63 sport fury, with a 426 wedge. The car arrived at my shop for a oil leak repair. Found the rear main to be leaking. Removed the main seal housing and found it to be cracked. Purchased a new seal ( lip type ) and housing from Mancini Racing. Installed seal, still leaking. Removed seal, called Mancini, talked to a tech, reinstalled seal according to their recommendations, ie clock seal, use only " right stuff " silicone, etc. let dry overnight before adding new oil. Started engine, still leaking!! I have done this job three times now and am sure its not installation error. I'm wondering if anyone else has had this problem? I'm also wondering if a lip seal just doesn't work in this application? I cant find a rope seal ANYWHERE to try that. Maybe when the car was restored the engine was not line honed properly? I'm pounding my head against the wall at this point. Any help would be greatly appreciated.. Thanks.