8 3/4 dimensions

[sydcuda]

I've just scored an 8 3/4 differential, 489 carrier. I will need to have the axles shortened for it to fit my 68 cuda. I'm trying to work out whether stock axle lengths will fo it for me, with the wheels and tires I have, or whether I will need to go to some other custom length.

Question is - Can anyone tell me what an A body 8 3/4 measures from drum brake to drum brake (that is measured from the tire mounting face of each respective drum)?

Cheers

 

[bOb shingler]

measure the one in your hotrod and see if they are the same or at least close.

 

[sydcuda]

well the existing diff is not an 8 3/4, just needed to know the correct width for an A body 8 3/4 to ascertain how much I will need to shorten the non-A body 489 unit I now have.

OK, I'll answer my own question in case somebody else needs to know. After much searching I found this info on Moparts.com. An a body 8 3/4 apparently measures 57 1/8 " drum to drum:

http://www.moparts.org/Tech/Archive/axle/17.html

 

[crackedback]

well the existing diff is not an 8 3/4, just needed to know the correct width for an A body 8 3/4 to ascertain how much I will need to shorten the non-A body 489 unit I now have.

OK, I'll answer my own question in case somebody else needs to know. After much searching I found this info on Moparts.com. An a body 8 3/4 apparently measures 57 1/8 " drum to drum:

http://www.moparts.org/Tech/Archive/axle/17.html

DO NOT USE THAT POS CHART!

The housing width for a stock A body is 52 5/8" NOT 51.40" like that chart says.

57 1/8" is correct for overall length. If you are using BBP axles, you need to shorten the housing under 52 5/8" to keep the same overall length. The brake standoff from SBP to BBP axles is different.

Go to the one link just above it, I think it's 16 in that list, that has the correct lengths for you to use.

 

[sydcuda]

Thanks crackedback!

 

[Moparmal]

A-body flange to flange

66-72 : 52-13/64"
70-71: 52-37/64"

 

[72chargerguy]

What about a '74 Scamp?

 

[sydcuda]

Check out the link to moparts above...it has all the dimensions

 

[Bill Dedman]

If, in fact, there are two different widths for A-Body housings, and Moser deals in MoPar hardware more than any other (and, so, should have accurate, comprehensive knowledge about this sort of thing), when I placed a phone order for my axles, why didn't he ask me what year my housing was (I told him I got it out of a junkyard)?????

With nearly a quarter of an inch difference in housing width, wouldn't that make an eighth of an inch difference in axle lengths?

Is an eighth of in inch just not really enough to worry about?

I wonder...