An accurate 8 3/4" rear axle width list

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72bluNblu

72bluNblu

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Ok, so, I've posted parts of this list a few times, normally in response to some of the really inaccurate charts and lists that are out there and posted too frequently. It's not my list, I sourced it from the internet but I can't remember where. Since the time I downloaded it several years ago, I have personally confirmed a bunch of these numbers. The A-body numbers, the E-body numbers, several of the B-body measurements, a couple of the C-body measurements, and even the D100 measurements. They've all been spot on, so I have no reason to suspect any of the measurements I haven't personally checked.

Everything is for 8 3/4 axles with the exception of the A-body 8.25 and BBP 7.25 measurements I added myself, and the F-body 8.25" measurements.

I also added the A-body BBP 8 3/4 width, that's for an A-body housing with axles that have the standard BBP axle flange offset and use 10x2.5" or 11x2.5" BBP brakes. It should be accurate within an 1/8".

8 3/4" Housing widths, flange to flange

A-BODY
  • '66-'72= 52 5/8”
    • BBP 7.25/8.25 = 51.5”
B-BODY
  • '62-'63= 53 1/4" (And '64 Max Wedge)
  • '64 = 55 5/8" (Exc. Max Wedge)
  • '65-'67= 54 1/4"
  • '68-'70= 54 15/16"
  • '71-'74= 57 7/8"
  • '71-'73 wagon= 59 7/16"
C-BODY
  • '65-'69= 56 3/4"
  • '70-'71= 57 7/8" (Chrysler & Fury)
  • '70-'74= 59 7/16" (and '69 wagon)
IMPERIAL
  • '65-'66= 57"
  • '67-'69= 57 3/8"
  • '70-'71= 54 3/4"
  • '72-'73= 59 5/8"
E-BODY
  • '70-'74= 56 31/64"
A100
  • '65-'70= 56 3/4"
D100
  • '65-'71= 58 5/16"
  • '72-'74= 59 7/16"
F-BODY (8.25" axle!)
  • ’76-’80= 54.34”
.........................................
........................................

8 3/4" Rear end widths, drum-to-drum:

A-BODY
  • '66-'72= 57 1/8” (or 57 13/16” for BBP axles and brakes)
    • BBP 8.25/7.25= 56 3/4”
B-BODY
  • '62-'63= 58 1/2" (And '64 Max Wedge)
  • '64 = 60 7/8" (Exc.Max Wedge)
  • '65-'67= 59 1/2"
  • '68-'70= 60 1/8"
  • '71-'74= 63"
  • '71-'73 wagon= 64 3/8"
C-BODY
  • '65-'69= 61.75"
  • '70-'71= 63.0" (Chrysler & Fury)
  • '70-'73= 64 3/8" (and '69 wagon)
IMPERIAL
  • '65-'66= 61 15/16"
  • '67-'69= 62 5/16"
  • '70-'71= 59 3/4"
  • '72-'73= 64 9/16"
E-BODY
  • '70-'74= 61 5/8"
A100
  • '65-'70= 61 3/4"
D100
  • '65-'71= 63 15/16"
  • '72-'74= 64 3/8"
........................................
........................................

Spring perch widths (center-to-center)

A-BODY
  • '66-73= 43"
B-BODY
  • '62-'70= 44"
  • '71-'74= 47.3"
C-BODY
  • '65-'73= 46"
E-BODY
  • '70-'74= 46"
F-BODY (8.25" axle!)
  • ’76-’80= 44.5”
 
Last edited:
Here's some actual axle lengths as well

8 3/4" axle shaft lengths (measured from the tip of the splined end to the outside of the flange)

A-BODY
  • '66-'72= 27 11/16"
B-BODY
  • '65-'67= 28 7/8"
  • '68-'70= 29 3/16"
  • '71-'74= 30 5/8"
  • '71-'73 wagon= 31 21/64"
C-BODY
  • '65-'69= 30"
  • '70-'71= 30 5/8" (Chrysler & Fury)
  • '70-'73= 31 21/64" (and '69 wagon)
IMPERIAL (Large Bolt Pattern)
  • '65-'66= 30 1/8"
  • '67-'69= 30 5/16"
  • '70-'71= 29"
  • '72-'73= 31 7/16"
E-BODY
  • '70-'74= 29 31/32"
A100
  • '65-'70= 30"
D100
  • '65-'71= 31 1/8"
  • '72-'74= 31 21/64
 
Does any body have any charts for the axle spline count. Trying to see if a 741 center from a 71 charger will be an easy swap into my 71 duster.
 
The centers are a direct swap with the same spline count. (if both rear ends are 8 3/4" of course).
 
As far as I know, all of the OE 8 3/4 3rd members have the same spline count. Now, if it was an aftermarket set up for drag racing it might be different. But I've never seen anything that said to even check the number of splines on an OE 8 3/4 3rd member to see if the spline count was the same as the OE one it was being swapped with.
 
One more time then. ;-)

The centers are a direct swap with the same spline count.
Click to expand...

I have swapped several over the years from A, B, & C bodies & 1/2 ton trucks & vans also. The stock axle splines are all the same regardless of 741, 742 or 489 case.
 
Alaskan_TA said:
One more time then. ;-)



I have swapped several over the years from A, B, & C bodies & 1/2 ton trucks & vans also. The stock axle splines are all the same regardless of 741, 742 or 489 case.
Click to expand...

Awesome... Thank you everyone.
 
72bluNblu said:
As far as I know, all of the OE 8 3/4 3rd members have the same spline count. Now, if it was an aftermarket set up for drag racing it might be different. But I've never seen anything that said to even check the number of splines on an OE 8 3/4 3rd member to see if the spline count was the same as the OE one it was being swapped with.
Click to expand...
This is correct. I've taken several 8-3/4's apart all the way from an early 60's unit to early 70's units (open's and sure-grips) and they all had 30 spline axles. Only aftermarket stuff is different.
 
blunblu A bit off of the subject, where do you get your rear end oil seals? Stock A body 8 3/4 489 case.
 
Any parts store should have axle and pinion seals....walk in with cash walk out with parts.
 
Glad to see this made it to sticky status! You're right blunblu, seems that every other day someone is looking for the correct information, and someone always chimes in with that old incorrect chart!
 
A-BODY
  • '66-'72= 52 5/8”
    • BBP 7.25/8.25 = 51.5”
Safe to assume 63-65 fall into this range as well?
 
72bluNblu said:
Ok, so, I've posted parts of this list a few times, normally in response to some of the really inaccurate charts and lists that are out there and posted too frequently. It's not my list, I sourced it from the internet but I can't remember where. Since the time I downloaded it several years ago, I have personally confirmed a bunch of these numbers. The A-body numbers, the E-body numbers, several of the B-body measurements, a couple of the C-body measurements, and even the D100 measurements. They've all been spot on, so I have no reason to suspect any of the measurements I haven't personally checked.

Everything is for 8 3/4 axles with the exception of the A-body 8.25 and BBP 7.25 measurements I added myself, and the F-body 8.25" measurements.

I also added the A-body BBP 8 3/4 width, that's for an A-body housing with axles that have the standard BBP axle flange offset and use 10x2.5" or 11x2.5" BBP brakes. It should be accurate within an 1/8".

8 3/4" Housing widths, flange to flange

A-BODY
  • '66-'72= 52 5/8”
    • BBP 7.25/8.25 = 51.5”
B-BODY
  • '62-'63= 53 1/4" (And '64 Max Wedge)
  • '64 = 55 5/8" (Exc. Max Wedge)
  • '65-'67= 54 1/4"
  • '68-'70= 54 15/16"
  • '71-'74= 57 7/8"
  • '71-'73 wagon= 59 7/16"
C-BODY
  • '65-'69= 56 3/4"
  • '70-'71= 57 7/8" (Chrysler & Fury)
  • '70-'74= 59 7/16" (and '69 wagon)
IMPERIAL
  • '65-'66= 57"
  • '67-'69= 57 3/8"
  • '70-'71= 54 3/4"
  • '72-'73= 59 5/8"
E-BODY
  • '70-'74= 56 31/64"
A100
  • '65-'70= 56 3/4"
D100
  • '65-'71= 58 5/16"
  • '72-'74= 59 7/16"
F-BODY (8.25" axle!)
  • ’76-’80= 54.34”
.........................................
........................................

8 3/4" Rear end widths, drum-to-drum:

A-BODY
  • '66-'72= 57 1/8” (or 57 13/16” for BBP axles and brakes)
    • BBP 8.25/7.25= 56 3/4”
B-BODY
  • '62-'63= 58 1/2" (And '64 Max Wedge)
  • '64 = 60 7/8" (Exc.Max Wedge)
  • '65-'67= 59 1/2"
  • '68-'70= 60 1/8"
  • '71-'74= 63"
  • '71-'73 wagon= 64 3/8"
C-BODY
  • '65-'69= 61.75"
  • '70-'71= 63.0" (Chrysler & Fury)
  • '70-'73= 64 3/8" (and '69 wagon)
IMPERIAL
  • '65-'66= 61 15/16"
  • '67-'69= 62 5/16"
  • '70-'71= 59 3/4"
  • '72-'73= 64 9/16"
E-BODY
  • '70-'74= 61 5/8"
A100
  • '65-'70= 61 3/4"
D100
  • '65-'71= 63 15/16"
  • '72-'74= 64 3/8"
........................................
........................................

Spring perch widths (center-to-center)

A-BODY
  • '66-73= 43"
B-BODY
  • '62-'70= 44"
  • '71-'74= 47.3"
C-BODY
  • '65-'73= 46"
E-BODY
  • '70-'74= 46"
F-BODY (8.25" axle!)
  • ’76-’80= 44.5”
Click to expand...
I have a slant six car and am changing to v8 car with 8.75. 8.75 "A body" rear end is currently sbp, changing to bbp. I'm trying to figure out backspacing for wheel without converting to bbp and disc setup and the having to possibly cut axle down. I want to run 6.38 BS. Car is completely torn down, going to mini tub and cut lip of rear quarter and possibly roll. Also have 3/4" shackle offset. Want to run a 295/40r18. Any help would be appreciated
 
Zcuda68 said:
I have a slant six car and am changing to v8 car with 8.75. 8.75 "A body" rear end is currently sbp, changing to bbp. I'm trying to figure out backspacing for wheel without converting to bbp and disc setup and the having to possibly cut axle down. I want to run 6.38 BS. Car is completely torn down, going to mini tub and cut lip of rear quarter and possibly roll. Also have 3/4" shackle offset. Want to run a 295/40r18. Any help would be appreciated
Click to expand...

So, is this for a '68 Barracuda like your screen name would suggest?

If it is, you're basically going to be running the same set up as I am with my Duster, except with a BBP A-body 8 3/4 in place of the B-body 8 3/4 I run. Assuming you're looking at an 18x10 for a rim, it's just correcting for the axle width change because the wheel houses are pretty much the same and we both have offset springs. The 18x10's I run have a 7" backspace, but I run them with drums at the moment. The B-body 8 3/4 I run puts the wheels out about 1.15" further than a BBP A body 8 3/4, so, you'd be looking at 5.85" of backspace to put the tires in the same spot. Most disk kits add 5/16" to 3/8" per side for width, so, add that in and figure about 6.15"- 6.22" depending on the disk kit.

Which means 6.38" is pretty darn close. More than likely you'll need a small wheel spacer to make it work, you'd be looking at about a 1/4" spacer. But that's assuming everything is identically the same, which is won't be. Bottom line is you'll have to measure your own car, but an 18x10 with 6.38" of backspace with the offset springs and a quarter lip trim should be in the ballpark with 295/40/18's with a BBP A-body 8 3/4 with rear disks if you run some kind of small spacer.

295/40/18's are about as tight a fit as you can make it, so, you will definitely need to make your own measurements and plan on making some adjustments to get the clearance you need. Feel free to send me a message if you want so we don't sidetrack this thread.
 
i just ahve a quick question, can a 8 3/4 from a 66 dodge charger be made to fit my 1969 dodge dart? i know the springs need to be relocated but im cool with that but will i need to have the housings cut?
 
1969moparDART said:
i just ahve a quick question, can a 8 3/4 from a 66 dodge charger be made to fit my 1969 dodge dart? i know the springs need to be relocated but im cool with that but will i need to have the housings cut?
Click to expand...

You don’t necessarily NEED to cut the housing. That rear axle will add a little less than 7/8 to each side for backspace compared to an A-body 8 3/4 with BBP axles. So, for example, a 15x7 with 4.25” of backspace isn’t s bad choice for a BBP a body 8 3/4, but to keep the wheel in the same place with the 66 B body a 15x7 would need 5 1/8” of backspace. That’s doable, but it would probably be a custom rim in a 15” diameter. In a 17” rim it’d be a piece of cake.

Just depends on what you’re doing.
 
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