Here is the dims of the 8 3/4 axles, yes the spring perches only have to be moved an inch inwards, but overall the diff is 4" wider: Because the 8-3/4" axle was available in most body lines, there are a variety of housings available. Following are some of the passenger car axle dimensions and notations. <br> The Perches dimension is the distance center to center between the spring mount perches. Body Line Track Perches Notes Dimensions are in inches. A-body, 65-72 55.6 43.0 B-body, 62-70 59.2 44.0 B-body, 71-72 62.0 47.3 B-body, 71-72 63.4 47.3 station wagon C-body, 64-72 63.4 47.3 D-body, 64-72 63.4 47.3 E-body, 70-74 60.7 46.0 Dodge, Chrysler, Plymouth Rear Axle Dimensions Rear Axle dimensions and diagram for Chrysler, Plymouth, and Dodge cars. Rear Axle's. covers A-Body, B-Body, C-Body, E-Body and F-Body. Year Axle (A) (B) (C) 1963 - 1972 7 1/4" A-Body 53.200" 43.02" 10.09" 1973 - 1976 7 1/4" A-Body 51.400" 43.02" 10.09" 1973 - 1976 8 1/4" A-Body 51.400" 43.02" 11.69" All 8 1/4" B-Body 57.800" 47.30" 11.69" All 8 1/4" C-Body 59.200" 47.30" 11.69" All 8 1/4" F-Body 54.340" 44.46" 11.69" All 8 3/4" A-Body 51.400" 43.00" 12.35" 1962 - 1970 8 3/4" B-Body 55.000" 44.00" 12.35" 1971 -1974 8 3/4" B-Body 57.800" 47.30" 12.35" All 8 3/4" E-Body 56.500" 46.00" 12.35" 1971 -1974 8 3/4" B-Body S.W. 59.200" 47.30" 12.35" All 9 1/4" B-Body 57.800" 47.30" 11.69" All 9 1/4" C-Body 59.200" 47.30" 11.69" 1966 - 1970 9 1/4" B-Body 54.936" 44.00" 13.47" All 9 1/4" E-Body 56.500" 46.30" 13.47" (A) = Flange to flange. (B) = Leaf spring centerline to leaf spring centerline.. (C) = Centerline of axle shaft to centerline of rear universal joint. Illustration & Information from Chrysler Performance Upgrades, by Frank Adkins. Published by CarTech as part of their SA Design series. Check the following link as well: http://www.mymopar.com/axledims.htm It is not a direct bolt in and offset wheels would have to be used if the axles are not narrowed as evident in all articles of the dims of the 8 3/4 A and B body. On Fri, Aug 8, 2008 at 10:37 PM, Dan McCormack <mcwheels@xxxxxxxxxxxxxx> wrote: > > Herb and Steve, I'm not saying you guys are wrong or mistaken because as we > all know "Never Say Never with Mopar" Personally I've never see a 73-76 A > body with an 8 3/4 factory rear end even in a 340 or 360 car. They've all > had a Spicer 8 1/4 in them. > > Again you can't believe everything you read but here's a quote from Auto > Hobby Digest: > > "All of the A-body 8-3/4's were small bolt pattern axles (5x4") without > exception." > > I do have to disagree with you Steve about the B body rear end however. My > friend is running a 68 B body rear end in his 73 Duster 340. He didn't have > to narrow the B body rear end but he did have to move the spring perches. > Here is some more info from Auto Hobby Digest: > > "Another 8-3/4" option is to use a B-body 8-3/4" rear end. There were > several different widths used in B-bodies during the sixties. The 1962-63 > B-body rear measured 53-1/4", It was changed in 64,65,66,and again in 68. > The 68-70 was approximately 55" wide. 1971 and later B-bodies are too wide > of candidates. On Dusters and Dart Sports, the wider rear end looks at home. > On early A-bodies (1963-66) its looks a little awkward. While the 1962-63 > rear end is only a sanct 3/4" wider than an A-bodies, its downside is that > the 1962-64 rear end uses a tapered axle that can be difficult to work with. > > All the 1962-70 B-body rear ends came with their spring perches 44" apart, > whereas the A-bodies were 43" apart. With any B-body rear end you will need > to move the spring perches inward 1/2" on both sides." > > > > ----- Original Message ----- From: "Steve Chervinsky" > <63hemipolara@xxxxxxxxx> > To: <1962to1965mopars@xxxxxxxxxx> > Sent: Friday, August 08, 2008 7:05 PM > Subject: Re: green bearing questions > > >> Chrysler used the 8 3/4 right into 74. And in A-bodies 73+ they were >> 4.5" bolt circle. My fiends original 73 Duster /6 had a 8 3/4 with a >> 489 case. Meanwhile my 63 Polara has the small 741 case and the stupid >> keyways for the drums. A B-body 8 3/4 will not fit an A-body without >> being narrowed. > > > ---- > Please address private mail -- mail of interest to only one person -- > directly to that person. I.e., send parts/car transactions and negotiations > as well as other personal messages only to the intended recipient, not to > the Clubhouse public address. This practice will protect your privacy, > reduce the total volume of mail and fine tune the content signal to Mopar > topic. Thanks! > > '62 to '65 Mopar Clubhouse Discussion Guidelines: > http://www.1962to1965mopar.ornocar.org/mletiq.html. > > > -- Steve '63 Hemi Polara ---- Please address private mail -- mail of interest to only one person -- directly to that person. I.e., send parts/car transactions and negotiations as well as other personal messages only to the intended recipient, not to the Clubhouse public address. This practice will protect your privacy, reduce the total volume of mail and fine tune the content signal to Mopar topic. Thanks! '62 to '65 Mopar Clubhouse Discussion Guidelines: http://www.1962to1965mopar.ornocar.org/mletiq.html.