rearend ? again

if anybody has read my other post i bought a 81/4 rear at a swapmeet with 355 suregrip suppose to be out of a 73 dart well after driving it a little bit the axle seal starting leaking i pulled the axle tonight never seen nothing like it the bearing stayed in the houseing looks like it's been sleeved and the bearings pressed in the sleeve the seal for the 81/4 is thick the one in it's thin anybody everheard of this the rear has no tag the numbers on it or 3723599 and 10325 it fit in my dart it didn't whine or make any nose? it don't have a rubber fill plug in the cover either? has a screw in plug on the side of the houseing makes me wonder what it's out of nobody has a seal 4 it either i'm gonna check napa tomrrow i got a # for it