Thanks Bill all the info I can get on the subject is welcomed (especially from you), so far I have 71 pages of data I've printed on the 9", 8", and 9 3/8. the only thing Ive found about the 9 3/8 is it came with the "trac loc" as a package. The one Im thinking of buying has an open carrier (housing notched for to accept posi) according to the seller, He says that's why it was changed out , because he had a posi one??? I don't know, Im reading all I can find so Ill be able to tell, hopfully.LOL Oh and thanks for the heads up on the Williams yard, sounds good. Im timing out here so I better rap up, thank you very much for the info. "ETIT" I have just read that the 9 3/8" will fit in a standard 9" housing but only if you grind two 1/8" notches so you can get the larger ring gear into it, the bolt pattern seems to be the same. Gear and shim support seem to be bad for the 9 3/8" I guess that is what the seller of the standard 9' that I am interested in means by it has been notched. So I should have no trouble finding a normal limited slip for it if I purchase it. Just in case anyone is interested.