Stock 59 chevy rear posi swap question ???????????

So I've done searched for past hour and I just give up. so heres what i have ,Its a stock rear out of my 59 chevy station wagon . I picked up a posi unit out of i think a 57 rear , witch from what im told the rears are all the same from 55-64 , SO here's what i herd , it would be a simple swap and I would be good to go. so heres the big delema
go to put the posi in and the rear axel carrier bering are the rong size and everyone i talk to says that all the rear axel carrier bearing for these rears are what the posi unit is, which is 1.627 I.D. and my 59 bearings are 1.782 I.D. Has aney one out there ran into this problem? or even know what im talking about , if so what did you do and aney help would greatly be appreciated.
The race measures od 3.150 and
heres a pic of my 59 bearing on the posi unit and the problem .



Thanks

 

Your posi unit may be from an early Chevy II, a 1962 - 1964, or so. My older brother, (hrbhrb here on The HAMB), ran into this problem in about 1971. The carrier bearings on his posi, were smaller than the bearings on his original 57 rear end. The hubs on the posi, where the bearings press on, were smaller, too.

 

thanks for the info , ill have to check into some more , but the thing is that my friend has a 62 posi unit out of an impala and its the same as my posi unit , so i guess ill keep on looking

 

Hi, Just to expand on what younger brother (Torkwrench) said. I had also gotten the idea that everything from 57 to 64 would interchange. I was given this posi and told that it was out of a Chevy II. and would fit my 57. As noted above the bearings are smaller (both id. and od.). In all other respects it appears to be identical to the 57 units. It is stamped CHEV with additional numbers (don't recall what), so the Chevy II theory seems plausible. I hope someone with more knowledge of this subject can clear up the mystery.
Bob

 

I recall taking apart a non-posi early Chevy II differential, the pinion bearings were different...but I probably didn't check the side bearings.

But a quick look at the rockauto online catalog might tell us what is going on.

http://www.rockauto.com/catalog/x,carcode,1491057,parttype,2240

http://www.rockauto.com/catalog/x,carcode,1324213,parttype,2240

looks like that might be it

 

sorry , you were correct

thanks squirrel

 

The Chevy II/Nova drop out third members are a light duty unit; even the casting is thinner, as well as having smaller bearings. Jump on over to ChevyTalk.Org, and read the stickies by DZAUTO/Tom Parsons. He's a wealth of knowledge on everything Chevrolet, and these rear ends are one of his specialties. Butch/56sedandelivery.

 

The posi unit that you have is 1962-1964 Chevy II Nova. It will not interchange with the full size 1955-1964 Chevrolet rear ends at all. You need a passenger car unit for sure. If your rear end center section has a 3 series gearset, you'll need a stock Chevrolet GM Arma Steel unit with a casting number of C-30743. Good luck on your search.

-Matt

 

Thanks everyone who helped me find out what this was , , it sure had me stumped ,

 

Tom is the man to talk to. He knows his stuff