8-1/4 to 8-3/4 rear end swap

[busteed]

I am currently dong a rear end swap to my 74' charger.  I need some information with someone who has done this.  Do I need to change anything on my car?  Shock mounts or leaf springs or anything else.  I just want to make sure I am ready for the swap.  if you can give me any other considerations for the swap that would be great. 
                BUSTEED

[Chryco Psycho]

the 73 -74 Chargers had an isloated spring mount, this can be eliminated & the diff can bolt directly onto the spring as in 64-72 B bodys ,   so you will need different shock plates & new U bolts & you may need to add shims to correct the pinion angle

[71charger_fan]

When I did the switch in my '71, the rear I initially got was from a '73. As Chryco said, the mounts were different so I found one in a '72 at the junkyard that was a bolt-in. Since the 8 3/4 I found had the small yoke, it even hooked right up to my driveshaft. I put the brakes from the 8 1/4 on the 8 3/4's backing plates, replaced the rubber brake line and the hard lines and was good to go.

[andy74]

When I did the switch in my '71, the rear I initially got was from a '73. As Chryco said, the mounts were different so I found one in a '72 at the junkyard that was a bolt-in. Since the 8 3/4 I found had the small yoke, it even hooked right up to my driveshaft. I put the brakes from the 8 1/4 on the 8 3/4's backing plates, replaced the rubber brake line and the hard lines and was good to go.

same here,although my soft mount rear came from a 73,i took it to a local spring shop,and they welded the spring plates with an thick steel washer,and i painted it to match,1000 hard launching trouble free miles since!!

[74Charger]

I did my 74' last winter.  I wanted it to go as easy as possible.  I got a 8 3/4" housing from a 72 road runner.  It fit like a glove.  It was the exact same measurement as my 74'.  Perches lined up exactly. Took the brakes from my 8 1/4 rearend.  And swapped them over to the 8 3/4"  The hardest part I had was finding a complete rearend that measured the same as my 8 1/4"  I ended up having to buy all the components seperate.   New Strange axles.  A used 742 third member off ebay with clutch suregrip.  Installed a new set of 3:91 gears.  A new set of u-bolts, and fluids.  It took me the better part of a weekend.  Between sanding,painting, pulling out. and installing.  I broke a bolt or two when removong the springs to sand and paint them.  I shoul d have just replaced them while I had them out.  Something to consider.  Here is some good info to help you out with.  If you do not already have it.

http://clubs.hemmings.com/clubsites/cowtownmopars/ChryslerRearEnd.html

http://www.440magnum-network.com/info/tech/rearaxle/moparrearaxle.shtml

   Tom-