[rainman1]

I have a '71 Malibu with a factory 10 bolt non-posi unit that just saw its last day. I now want to upgrade to a 12-bolt posi differential. Which units will interchange with a '71 Chevelle? Is it any '68 to '72 A-Body? Is there anyway to tell by coding on the differential itself? I know some yolks have "lips" that ensure the U-Joint is centered properly (like mine now)and others dont. Anyway, if possible, I would like to find a 12-Bolt that was originally out of a '71 Chevelle. Any help would be greatly appreciated...Thanks in advance, Tom

 

[halldor]

Rainman it´s a matter of measuring,if you want a 12-bolt,it can be a tough task to locate one,but there are lots of Mustangs and
Cougars in the junkyard,right?I think the Mustang and Cougars rearend will fit,only a matter of an inch or an half,and much more plentiful,you only need to weld up a new spring mounts and new mounts for the arms.If the thought of a Ford component is not appealing,just look at the specs of this piece and availability it offers in hop up components.I am currently using a B-O-P,rearend,which is the same size as the Chevelle,it´s from a ´68 Skylark,if you find a A-body with a 12-bolt you can use it.
Just my thoughts,Happy hunting
HR

 

[DZAUTO]

ANY 65-72 12 bolt from a GM "A" body will physically bolt up and drive away. The 65-67 is a little over 1in. narrower hub-to-hub. So if you used a 65-67 you would need to check your wheel offset. The 12bolts are just like anything else that you are looking for. When you are trying to find one, it's impossible. If you are not interested in one, they're everywhere. I finally gave up on finding one for my 70 conv. Then one day I stole a 3.07 12bolt posi for $100. All it needed were some of the bearings replaced.

------------------
Tom Parsons