Narrowing a rear end.

[Crazy440]

I have a 8 3/4, that I need to have narrowed. How is this usually done?  Do they put it in a jig or do they put it on  a lathe?  Also, what's the procedure for cutting down axles?  Can the splines be extended up the shaft?
Thanks

[John_Kunkel]

To narrow the housing, the housing ends are removed and shortened the required amount, then a bar is placed in the housing that extends past the housing ends, bushings in the housing ends keep them aligned with the housing while the ends are welded back on. The link below shows the axle shortening/resplining process. In general the axle must be shortened at least 3" in order to have sufficient material for resplining.

http://good-times.webshots.com/album/563553900rszswA

[Crazy440]

Thanks for the info.

[Crazy440]

In general the axle must be shortened at least 3" in order to have sufficient material for reslining.

Been thinking of the above statement.  I have a 70 "B" body 8 3/4 going into a 72 "A" body.  The measurements are as follows
B body 55" flange to flange
A body 53.2"       ""
Diff of 1.8"
So, keeping your statement in mind, I would not be able to use the axles from the 70 8 3/4 and have them re-splined.  Correct?
I'll ask your opinion, here.  With less than an inch difference, on each side.   Why not just move the perches and use the "B" body as is?
Thanks

[idahogrumpy]

I have actually put the B body rear end of that year in an A body with out moving the perches. The springs were a little tweaked, but it worked. Yes a real back yard job I know.  Get yourself an 8 3/4 out of a Chrysler something, narrow it and go with after market axles.  Bigger brakes most of the time and with new axles will be much stronger. Save the 70 rear end for that next b body build.   
Grumpy

[John_Kunkel]

To shorten an axle for use in a stock width A body housing, the finished axle will measure 28" so the axle must be at least 31" to start with; this narrows it down to:

B BODY
'71-'73 wagon= 31 21/64"

C BODY

'70-'73= 31 21/64" (and '69 wagon)

D100
'65-'71= 31 1/8"
'72-'74= 31 21/64