Question on rear end case #

[troy.70R/T]

I am parting out a 67 Coronet. I am useing the drive train for my charger. The rear end in the Coronet is a 742 open 3:23. I have not had time to jack up my Charger and find out what it has. I think it has 3:23's as well but I am not sure of the case # What would a 68 Charger R/T 440 car have came with as far as the Case #? Is the 742 a better case #? Just wondering which one to keep and which one to sell. Thanks

[Ghoste]

68 should still have a 742 and they are a good case.  Large pinion, shims clutch type limited slip.

[troy.70R/T]

I do plan on putting 3:91 gears in it later on. Will the center sections inner change? I guess I better Check to see what my Charger has before I sell anything. Thanks John

[troy.70R/T]

I might also put a spool in it later on down the road. I would like to build a Dana for it someday so I dont want to get to crazy on dumping a lot of money into the 8-3/4 yet.

[Ghoste]

They do interchange.

[troy.70R/T]

Thanks Ghoste. I read a link somewhere on the specs of the 742 741 and 489 case but I cant find it anymore. I remember one was a tapered pinion and one was bigger but don"t remember much more than that. I went to Moparts but found nothing. Anyone know of a link?

[Ghoste]

I thought Moparts had a good primer on them?  Maybe I just remember incorrectly but there is also likely some good info on it here someplace and I expect anytime that John Kunkel will jump in and tell you all you could ever imagine.
The 489 case that came along in 69 has the tapered pinion and many consider it to be the tougher of the two but really in a street car its potato-potahto.

[troy.70R/T]

Thanks again Ghoste I am goin to look a little more on here. Maybe I missed it on Moparts

[Ghoste]

http://www.moparts.org/Tech/Archive/axle/21.html

[troy.70R/T]

Thats what I was looking for. Thanks Ghoste.

[fy469rtse]

Should be 742 's in both , like ghoste said will interchange , look for tags to pig bolts , might give you an insight to what's inside LSD centre , only weak point with 489 , crush sleeve, there's a kit to replace that, but use the 742's

[troy.70R/T]

Thanks. I was reading on moparts and see thst the 67 coronet rear is a little narrow. I am not sure  but would it boltt up into my charger? I would like a narrower rear so I could fit my 10 inch slotted mags under the car better.

[John_Kunkel]

The 489 was introduced in mid model year '68 (January 9 to be exact) but only with certain ratios.

[troy.70R/T]

Thanks John I am going to check my 68 to see for sure what it has this weekend. I was pretty sure my charger had 3:23's but that was about two years ago when I bought it and checked it at the time.

[HPP]

I have drag raced all three cases. In my bracket applications on prepared tracks with slicks, I've never hurt any of them, even the maligned 741 set ( which, by the way, is still bigger than some chevy pinions). Did I run them long enough to fail, no, I typically was changing out to another ratio at some point. Would they eventually fail, maybe.

Now if I was putting down more than 400 horses to the tires (in reality, not mathematical) launching above 4500 rpm on big tires, or using a manual trans, I'd definetely go with the Dana. For a basic street cruiser with an auto, any of the three will be fine.

[Ghoste]

I agree, I'd sooner race a 741 than a 9 inch Ford personally.

[troy.70R/T]

Thanks for the input HPP. I guess they must hold together otherwise there wouldnt be any left.