8 3/4 Rear Identification

[Dana67Dart]

Hello my B-body Brethren!

Just picked up a junk yard 8 3/4. It was in a bone pile so I don't know what it is out of and some of the measurements are not adding up from the various sites that list such. The yard didn't have but 2 mopers in the 60 to 70s range, one was a 68 Belvidere and a 70s duster with tubs neither had a diff in it.

Most things add up to 70 to 74 E-Body but some things don't add up...

Details:

Breather is up on the hip of the housing not on the flat of the tube.

Large bolt pattern

Left hand threads on left axle

OE axle bearings

Both axles look identical

One axle measures 30 inches on the end of spline to out side of wheel flange.
65 to 69 C body or 70 to 74 E body or 65 to 70 A100

One axle measures between 30 1/16 to 30 1/8 end of spline to outside of wheel flange.
65 to 66 imperial?

Perches under housing

742 with Sure Grip / Power-Loc gears say 12 / 66 for date.

There was no tags on the diff, probably was apart at one time.

Small flange u joint

Drums have springs around the OD

Housing measures 56 1/2 out side axle mounting flange to outside mounting flange.
70 to 74 E body?

Purch CL to purch CL 46.
65-'73 C BODY
70-'74 E BODY

Brakes are 11 x 2 1/2

What do you all think?

Also everything but the center section will be for sale in a week or so. PM if interested before its posted.

 

[multimopes]

I am sorry that I can't help you but here is a belated Welcome Aboard!

 

[khryslerkid]

http://www.moparts.org/Tech/Archive/axle/16.html

Perch measurement is center to center.

I'm leaning toward the 65 to 69 C body. Pre 1970 had the vent up higher on the housing.

 

[beanhead]

http://www.moparts.org/Tech/Archive/axle/16.html

Perch measurement is center to center.

I'm leaning toward the 65 to 69 C body. Pre 1970 had the vent up higher on the housing.

I'm with Kid...not many(if any)'742' centers made it into the E-bodies, as Ma started switching to the '489' case in 1969...things could have been swapped over the years though. Small u-joint on the '742'? 7260 and the older outside snap-ring style(1310?) were very close in cap diameter. The center you have can be desirable but the housing/axles not so much, would need some cutting for use on a B-body

 

[Dana67Dart]

I am sorry that I can't help you but here is a belated Welcome Aboard!

Thank you
I'm trying to unravel this mystery before I sell it!

 

[Dana67Dart]

I'm with Kid...not many(if any)'742' centers made it into the E-bodies, as Ma started switching to the '489' case in 1969...things could have been swapped over the years though. Small u-joint on the '742'? 7260 and the older outside snap-ring style(1310?) were very close in cap diameter. The center you have can be desirable but the housing/axles not so much, would need some cutting for use on a B-body

I'm fairly confident that the center was swapped as the date on the gears and sure-grip are 1966 and the housing flange width is 70 -74 E-body but I'm still baffled by the breather location. 66-69 Station wagon maybe?

 

[Dana67Dart]

Took some photos.

56 1/2 flange to flange (Assuming Moparts' dimensions are correct it can't be any thing but 70-74 E-Body)
46 CL perch to CL perch (yes the photo is left side to left side but that's the same as Cl to CL, 65-73 B-Body or 70-74 E-Body)
Breather on the hump pre 70

Any thoughts on the "2" stamped next to the perch?

 

[khryslerkid]

This chart is a little easier to read. Looks like the "E" body.

 

[Lefty71]

Wouldn't this be a 1966 or 1967 only C body unit??? 66-7 used the left hand threads for sure... they used them til '70, but I thought the axle would be wider starting in 68, and there are no E bodies with left hand studs????? maybe 70 only, but wrong date code on the diff....

 

[beanhead]

Looks like E-body dimensions...time to call in the experts! That chart doesn't show any C-body 8-3/4 sizes..
@Cranky

 

[Lefty71]

This chart is a little easier to read. Looks like the "E" body.

Am I missing something?? There are no C bodies with 8-3/4 on that chart...

 

[khryslerkid]

Am I missing something?? There are no C bodies with 8-3/4 on that chart...

There use to be a good page on mopar rears, easy to read and all of the correct info. All I
find now is reformatted pages and lots of errors.

 

[Dana67Dart]

I have been told by numerous sources that that particular chart is not very accurate.

I agree that the rear screams E-body except for the Breather location being a 69 and older location. Could be an early 70 housing that was built in 69 and maybe the change over happened mid run.

 

[Dana67Dart]

there are no E bodies with left hand studs?????

Info I have seen has left hand threads to 70 but not in 71

 

[khryslerkid]

That breather location changed somewhere, late 60s early 70 on the E body, maybe even on the A body. Need the E/A experts

 

[Dana67Dart]

http://www.moparts.org/Tech/Archive/axle/16.html
Seems to be complete but I don't know how accurate it is. Many on FABO think it is correct.

 

[Fran Blacker]

Think 72 was last year for left wheel studs but not sure.

 

[Dana67Dart]

That breather location changed somewhere, late 60s early 70 on the E body, maybe even on the A body. Need the E/A experts

FABO agree that vent changed between 69 /70. 69 and older on hump, 70 and newer on tube.

 

[Cranky]

I had a 72 Challenger back in 74 and it had left handed lugs on it.....and that housing appears to me to be an E body housing. All of this stuff varies some but the spring pads are usually pretty close surprisingly. There's a pair of axles in the rafters that measure 30" on the money and they came out of a 66 B. The housing measures 54 1/4" just like the Moparts chart says it should but I've measured them at 54 1/8 and 54 3/8 and everywhere in between. The Moparts chart says they should measure 28 7/8 but mine are 30". Anyways, the mid 60's cars generally run close to 1/2" shorter (never found one shorter than 1/2" over the 68-70 cars) than the 68-70 B's which generally run 2" shorter than the E cars.

 

[Cranky]

Btw, the 29 31/32nds" (about .030")is well, nuts lol for the E cars. The tolerance wasn't even close and the adjuster can take up how much?? And the 56 31/64" for the housing.....well, that's 56.4844 lol. The way these cars were built back then, I highly doubt they used 64ths (about .015") or even 32nds to take measurements on the chassis. The body was way worse. The chart from Moparts may have come from some members who just happened to have a housing and axles handy to check and that's the measurement that got on the chart. I don't know but measuring 64ths is just being **** imo.