Putting a B Body 8,3/4 rear end on a A Body

[1968Coronet500]

Can someone tell me what kind of back spacing I'll need if I convert my 1971 Valiant's 7,1/4 to a B Body 8,3/4? My brother gave me his 3:23 posi unit that was out of his Coronet. I was planning on going to big bolt pattern in the front with disk brakes and the factory Rally wheels all the way around, but I'm not sure of the spacing issues.
Thanks

 

[GotDart]

Depending on what year B-body axle you have, it is either 1.8" or 4.6" wider from flange to flange than the original axle. So divide that by 2 and add it to your current backspacing to get the wheels in the same spot.

This chart in BBD might help you figure it out.

http://www.bigblockdart.com/techpages/diffchart.shtml

 

[gremlin]

Becarreful using that chart. Some of those numbers are wrong. Go to their forum and look for 8 3/4 to short. One guy used the chart numbers and cut his rear end a couple of inches short. There are a few other posts reporting the numbers as wrong, also.