First lets start with the Bearing info that is needed for the 300ZX T or the Q45. Im going to toss out 1995 or later, but that part I can not confirm or deny so please note that this is just speculation.
The center bore should be 1.811 not the 1.69 that the NON TT versions are

Federal Mogul makes these under "National Wheel End Components" They list the part number as 511011.
Beck Arnley makes these. They list it as part 051-4025
Timken DID list these as 511011, but now that part number is for the NON TT. It has been a pain that they use the same part number for 2 different bearings. posting.php?mode=post&f=315#
Value Pro listed these as well, but again their part number is for the NON T
SKF lists a bearing under 511011 BUT I have not confirmed the center bore.
I have seen them listed for as little as $75, but the part has been the wrong inner bore.
The major name part houses list these for about $500!!!! posting.php?mode=post&f=315#
Any additional info would be great. Feel Free to add.
The BA part can be found for about $250
