I have a posi rear out of a 1968 olds 88 four door.
Will the posi unit or gears fit in any of the smaller car rears like the 8.2 or 8.5 or type o rear.

 

NO.That is another type of rear that is unique to itself.I think what you have is what I call the large 12-bolt.A large 12-bolt cover,with a 12-bolt ring gear,and 31-spline axles.Did the car come with a 455?

 

12 bolt cover and 12 bolt ring gear bolts too.

'S' spring in the middle 31 spline axles BOLT IN AXLES.

does it look like this one?

Will not fit any other housing but the one pictured.

 

Yes the car had a nice c head low mile 455 thats going in a 68 cutlass.
The rear looks like the one in the pic,It has tall gears in it anyway,and the cutlass is getting a four speed and needs a low screw. thanks for the info

 

The Deltas from the same era,that came with the 350,came with the O-axle pumpkin,and 28-spline axles.I have gotten a few nice #671 posi units & 3:08's from cars like those,and put them into the A-body O-axle housings.
Among other creative things,I took the 31-spline shafts,from the rear above,along with a 31-spline #672 carrier,some 3:42 gears,and installed all of that into a 350-powered delta,with the O-axle.Someday,that's gonna make someone scratch their head.

 

The Deltas from the same era,that came with the 350,came with the O-axle pumpkin,and 28-spline axles.I have gotten a few nice #671 posi units & 3:08's from cars like those,and put them into the A-body O-axle housings.

Have never seen this before...???

I will have to double check some deltas in the yards as ALL I have ever seen are the Full size olds under the full size cars.???

I wonder if the D88 has the same chassis as the 68-70 LeSabre? Because The 68-70 LeSabre has a A-body 10 bolt 8.2 CENTER CASTING rear under it from a Skylark center...??? It does have longer tubes and lower mounts etc. then the skylark, But the same upper control arms ear offset. Interesting...AS I say - You never know everything - Something new all the time.

So Brian are you saying the delta 88 have the same upper ear casting as the a-body or are you say they used a totally new 12 bolt 'o' type (10 bolt gut ) cast center with the normal WIDER spread full size car upper ear location for the delta 88??? Bit confused on this one............... Jim

 

The 350-equipped Deltas,or at least the ones I have had or seen,came with the O-type rear,with the 12-bolt cover/10-bolt ring gear,just like the A-body O-type.The carrier,gears,and cover are the same. It's been awhile since I had one,but I am pretty sure that the pumpkin itself is a different casting,and the ears are farther apart or pitched different.
I have never found one of these under a smallblock LeSabre,or anything else.There were a whole slew of 60's/70's fullsize GM's at the local yard,but I really never bothered with them,unless I got the oddball request to do a rear for one.I've been under a few early 70's Rivieras,with the big rears.I do think the frames & chassis are different between the Olds,Buick,Pontiac fullsizes,or at least from what I saw,something was always different from one to the other,but again,I didn't pay too close of attention to them.

Could the 350-equipped Delta be ordered with the bigger rear? I'm sure that was possible too.
I thought that kid was on this site that I did that concoction for,maybe not.

 

Was it me? I recall getting axle shafts from you years ago with 671 carrier and gears for my 69 88 sbo.

 

I think it was you. I haven't done too many Delta rears. One guy lived overseas,which isn't you,but I think your parts/set-ups were the same.

 

My memory decided to surface and I recall getting some 28 splined axles with 3.08s from you. I could not have been the person you sent the 31's too.
So Abody rears and Bbody small block rears are interchangable. And Bbody big blocks are also?
So I can use the 31 splined axles from a big body big block olds and bolt it to my big body small block rear with 671 carrier?
Anyways, it's intresting how interchangable the rear ends are for Olds in the same era. Was there anything special you had to do to make the big body big block (new acronym? BBBB) rear fit into the big body small block rear?
Ed

 

I do remember yours.I did go a step beyond that.I took a set of 31-spline axle shafts,from a 455-equipped delta,with the large 12-bolt rear,and installed them into the Delta O-axle,along with a 31-spline #672 carrier,and a set of 3:91 gears.

 

Hey 507 olds, I posted a thread similar to this, I have a 69 98 with a 455 which monzaz says would be the 12bolt gear. So could i use a 671 31 spline carrier and then use a 3.42 10 bolt ring and pinion in my olds? or would pinion depth be diff.?

 

NO.You have the large 12-bolt,and they do not make any aftermarket parts for those.Every once in awhile,you might see a set of 3:23 gears come up for sale,for one of those,but that's about it.Then you need the posi to match it.