8 3/4 right size for a body ?

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grassy

grassy

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Hi,

Just checking some things before we get into the thick of it..so if I need to do something, I can do it now. I know I sound like a nervous nelly but we have hit walls in the past ... I have a few more suspension questions but I'll ask those in the future.

According to Moparts , the A body 8 3/4" Rear End Dimensions '66-'72 ( I am assuming that these numbers go up to '76) needs to be 52 5/8 from flange to flange. That that would be my inner measurement. I don't see the term flange on any of the exploded diagrams in the '75 manual

measurments-X2.jpg

 
A body rear should be 52 5/8" flange to flange.

What is the measurement you have from center to center on the spring perches.

I'd say you have an A there.
 
Yellow arrows show the flanges, that measurement should be 52 5/8". Red arrows show the center of the perches, that should be 43". :D
 

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Is that 52 5/8 to the inside of the flange or outside of the flange. I have checked on several websites and get different numbers. I believe the 8 1/4 from 73 up are a different length. The mopar website states the 66-72 A body rear at 52 13/64 while the 70/71 A body rear is 52 37/64 which is 3/8 " difference. Confused yet; I am. Can anyone clarify the correct measurement and where is it taken from? Thanks
 
:)

Gotcha. I understand now.

I shall measure tonight so I can rest easy. This was one of the parts that came with the care so I don't know it's origin.

ian.
 
grassy said:
:)

Gotcha. I understand now.

I shall measure tonight so I can rest easy. This was one of the parts that came with the care so I don't know it's origin.

ian.
Click to expand...

You will encounter a couple of small issues when you switch it out, so keep this thread alive. I assume you are removing a 7 1/4?
 
cobrabike said:
Is that 52 5/8 to the inside of the flange or outside of the flange. I have checked on several websites and get different numbers. I believe the 8 1/4 from 73 up are a different length. The mopar website states the 66-72 A body rear at 52 13/64 while the 70/71 A body rear is 52 37/64 which is 3/8 " difference. Confused yet; I am. Can anyone clarify the correct measurement and where is it taken from? Thanks
Click to expand...

52 5/8 is suppose to be outside to outside. Now with that said I have built a many of A-body 8 3/4 and have found them a 52 7/16 to 52 11/16. I don't think quality control was that great back when they were being built.
 
Bad Sport,

Yes..it has already been take out and it is at it's new home.

I have the 8 2/4 hardware to install. Since a a727 is being installed as well, the driveshaft length has to change. What should I be looking for ?

Any help is always appreciated.

Thanks
Ian.
 
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"



Housing widths, flange to flange

A BODY
'66-'72= 52 5/8"


Rear end widths, drum-to-drum:

A BODY
'66-'72= 57 1/8"


Spring perch widths (center-to-center)

A BODY
'66-73= 43"
 
grassy said:
Bad Sport,

Yes..it has already been take out and it is at it's new home.

I have the 8 2/4 hardware to install. Since a a727 is being installed as well, the driveshaft length has to change. What should I be looking for ?

Any help is always appreciated.

Thanks
Ian.
Click to expand...

When you install the 8 3/4 the brakes are larger than the 7 1/4. When I swapped mine out I was told I needed different emergency brake cables. I found out if you loosen the adjustment under the floor/front seat passenger side that the original cables worked just fine. If you don't loosen that adjustment you can get one side of the cable hooked up but not the other. It left me scratching my head for a minute. LOL

Check your pinion angle as well.

Other than that it should plop right in there.
 
SGBARRACUDA said:
52 5/8 is suppose to be outside to outside. Now with that said I have built a many of A-body 8 3/4 and have found them a 52 7/16 to 52 11/16. I don't think quality control was that great back when they were being built.
Click to expand...

Yep QC sucked. They were all over the place, usually within 1/8" either side of 52 5/8"

52 5/8" is the general width to go by for flange to flange.

The info Joe posted you can't go wrong with. If you swap to BBP axles using that bearing standoff, it makes the drum to drum about 3/4 wider in total than the std 57 1/8".

You don't have to fight with the center hole to find center to center on the perches. Have the tape grab the outside edge of one perch and measure to the inside edge of the other, that will get you a good measurement!
 
Bad Sport said:
When I swapped mine out I was told I needed different emergency brake cables.
Click to expand...

Now you tell me :)

I was told the same thing and I cut the cable running from the seat back. I believe I have the old assembly.

I have been looking at buying a new one but quite frankly, I don't understand their measurements.

But that question will be for later.

As soon as my son gets home, we are heading out to measure the axle.

Yes, I agree, qc was sometimes iffy..

Thanks
Ian.
 
Good news.

The measurements are just about perfect. One less thing to worry about.

Thank-you.

Ian.
 
Like the great philosopher and thinker of thoughts Forrest Gump once said...."Thats good, one less thang"......
 
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