8.75 (72 rear) conversion to a 73 Charger

[Beer]

Scored what I am told is a 3.91 (seems to be right based on turning the axle and counting the turns) Sure grip (remains to be seen, when I turn the wheel, the other one spins the other way-of course the yoke spins as well) from a 72 Charger.  I plan on converting my 8.25 open rear in my 73 to the 72 8.75 rear.

Its a 741 casting.  The Drums are different on each side, think that was an attempt to cover my Drum to drum request...

Here are some pics.















Hopefully going to disassemble it tonite.

Suggestions for refurbishing? Leaning towards a Summitracing Disc Brake conversion (up for other suggestions).

Disassembly pics to follow.

[Nacho-RT74]

will need:

-change axle pedestals to 73 kind, or

-use 72 lower spring plate and get rid off the isolator assembly, plus enlarge a little bit the center hole of pedestals or remove bushings mounted on spring guide stud, used to fit better on isolator assembly.

I think already talked about this somewhere LOL but with more detailed info... weren't you?

Do you have rear sway bar ?

Sure grip (remains to be seen, when I turn the wheel, the other one spins the other way-of course the yoke spins as well)

what?... that is simpthom of open diff not suregrip...If I understood right!

[Beer]

No to the sway bar Nacho  (not yet anyway)...Do I need to get one?

Looks like I did good... it is a Sure Grip...










Suggestions for  a rear disc brake kit for it

While I have the diff out should I have the Dodge Dealer freshen it up with new Mopar Performance P4529484 Clutch kit?

Is this worth doing and is it compatable w/ a disc brake conversion a Mopar Performance P5249444 to eliminate the production bearing retainers and axle end play adjuster

[Nacho-RT74]

no you DON'T NEED to get one, just if wished. My question was that depending if you got the say bar assembly, then what would it be the best way to made the modifications. Depending of that, you need to get 71/72 sway bar assembly or 73/74 when you wish to get one.

[firefighter3931]

Jim,

Your one stop shopping for rear end parts is Dr Diff (Cass)....he carries everything you will need. 

(1) Cass has nice rear disc conversions for the 8 3/4
(2) The MP clutch SG rebuild kits have some issues....some machining to thin out the plates is often required. Cass carries the correct kit, no machining required.
(3) The green bearing upgrade is fine. If you decide to go that route make sure to get the 2 piece bearing set....Cass has these as well. Once you upgrade to the grrens there is no more axle endplay adjustments. The thrust block needs to be removed from the SG unit when it's apart.

Read here for some green bearing discussion : http://www.dodgecharger.com/forum/index.php/topic,46515.msg510809.html#msg510809

(4) I would recommend a new installation kit...replace all the bearings while you're in there. 


I'd say you did very well on that purchase.....the 3.91's are a Great choice for your intended use. 


Dr Diff contact info: doctordiff@gmail.com  (406)883-4772



Ron

[Beer]

Thanks guys, what I think is odd is this came out of a 72 318 car???  BTW I got it from the guy that sells on Ebay from Eagle Lake, Maine (forget his user name), but he definately gets a thumbs up from me!  I am heading up there in the Spring for more parts (as the car tranistions from paint to assembly...) he told me he has a full hide a headlight clip on one of the (3) third gens he has up there (if anyone is interested)...

Ron just sent Dr Diff an email.  I document the upgrades like I did my stroker project...


Thanks



Jim

[firefighter3931]

Thanks guys, what I think is odd is this came out of a 72 318 car??? 

Jim, the 741 centersection is definately not stock for a 72 vintage car....if it was all stock it would have a 489 case. Someone swapped it out at some point and did you a favor. 

Looking forward to some progress updates....your threads and pics are allways informative and well written. 



Ron

[Beer]

LOL that would explain the Blue Silicone all around the casing seal to the diff...hopefully it was set up right. Will get all that checked out.  This should be a good year for this project to show some huge progress.  Many Threads coming from me in 2009 going to keep you and Nacho busy with stupid questions or advise.

[Nacho-RT74]

not too much about help with axle adjustments LOL... I'm on that deal...

http://www.dodgecharger.com/forum/index.php/topic,52373.0.html

Beside that SG unit should it be cone kind for that year since clutch ( Dana ) was replaced since by 69/70 for the cone kind ( Borgn/wagner ... sp ??  ) . 741 was still available Ron, 742 was the one replaced... thats what at least I know. My car had 741 from factory and is a 74


But clutch kind is easy to rebuilt if needed at home if required, thats the advantage. Cone kind needs a machine job.