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7 1/4 starting to get noisy - should I swap or rebuild?
https://www.slantsix.org/forum/viewtopic.php?t=15191		 Page 1 of 2
Author:  63Dart [ Mon Nov 28, 2005 5:58 pm ]
Post subject:  7 1/4 starting to get noisy - should I swap or rebuild?
Hi all,

63Dart here after a long away.

My 63 Dart's 7 1/4 is starting to get a little noisy.

I'm thinking about getting a larger rear-end (8 1/4 or 3/4).

I'd also like to go to 4.11s.

Right now, I'm running a 225, bored .060 over, Offy intake with two BBSs, custom cam, ported and polished and shaved head, Clifford 6x2, with two flowmaster 40s, and pertronix. My powerband is about 2500 to 5000 rpm.

Question #1 - do I really need a 8 3/4 with my 904 auto? (Or should I just rebuild the 7 1/4?)

Question #2 - if not - what's a good, easy to find rear that will fit?

Question #3 - does anyone in NorCal have one they want to sell???

Thanks!!!
Author:  mopar_nocar [ Mon Nov 28, 2005 6:28 pm ]
Post subject:  questions
#1 if you aren't racing A lot the 7.25 can hold up. i had one behind a 318 4bbl for a long time

#2 an 8.25 rear from any early a body is basically a bolt in. my 65 b-cuda rear end has the same mounting flange points as the one i pulled from a 74 Valiant. so that might help expand your potential donors. i have one, but its here in TX. kinda' hard to ship it to ya' for a reasonable rate.

#3 west coast differentials (www.differentials.com) have the gears and install kit you want if you plan to go back with the 7.25. (or any other rear for that matter) i have a set of 3.55s from them and an install kit too if you are interested.



sb
Author:  slantvaliant [ Mon Nov 28, 2005 7:30 pm ]
Post subject: 
Hey, mopar_nocar, what part of Texas?
Author:  Charrlie_S [ Tue Nov 29, 2005 4:41 am ]
Post subject: 
I am a fan of the little 7 1/4 rear. With a Sure grip unit, they will take a lot more abuse, then they are given credit for. That being said, unless you have a SG. and can rebuild the rear, correctly, yourself, I think I would look for a 8 1/4. Gears and SG units are easier to find. An "A" body 8 3/4 is getting quite hard to locate, and prices are nuts. It's almost cheaper to get a wider 8 3/4 and have it cut down to fit. I understand an 8 inch Ford rear from certain Mustangs, Granadas, etc, with the 5x4.5 bolt pattern will bolt into an "a" body. Depends on the supply in your area (not many around me).
Author:  mopar_nocar [ Tue Nov 29, 2005 6:25 am ]
Post subject:  location
i'm in San Antonio.

sb
Author:  slantvaliant [ Tue Nov 29, 2005 7:02 am ]
Post subject: 
I'm still looking for a rear for my '64 Valiant, primarily to get the large bolt pattern all around. I found a 5-lug Maverick a while back, but they crushed it before I got the cash and time for a harvest.
Author:  63Dart [ Tue Nov 29, 2005 12:49 pm ]
Post subject: 
Wow everyone - thanks for the quick replies!

I actually don't do a lot of racing (floor it to get on the freeway once in a while, that's about it).

mopar_nocar - I'm thinking that the 7 1/4 kit that you have might be the ticket. I've got a good mechanic on this end who probably could install and set the lash correctly, etc.. (Or I could try it).

3.55 sounds about right - I've got 3.23s right now, and a little more oomph would be nice.

If you want to make a deal on the parts - you can email me off line at kevin.sheila at the domain gmail dotcom. Or send me a private message.
Author:  SlantSixDan [ Tue Nov 29, 2005 1:32 pm ]
Post subject:  Re: questions
Quote:
an 8.25 rear from any early a body
No such item. The first year for the 8-1/4" rear axle in A-bodies was 1973, which puts it in the category of late A-bodies.
Quote:
west coast differentials (www.differentials.com) have the gears and install kit you want if you plan to go back with the 7.25.
These parts are still generally available, for the 7-1/4" rear axle was used in base Dakotas from '87 through '96. The complete rear axle won't interchange, but the ring and pinion, internal parts, etc. are all the same.
Author:  63Dart [ Tue Nov 29, 2005 6:29 pm ]
Post subject: 
Yes - the more I think about it - the more I like the idea of rebuilding the 7 1/4.

I checked out the website for www.differentials.com and they have a whole slew of gear ratios for the 7 1/4.

k
Author:  volaredon [ Tue Nov 29, 2005 7:01 pm ]
Post subject: 
Hey, if you need parts for your 7-1/4, don't hesitate to buy from mopar_nocar... he's good people. Done a couple of parts deals with him lately! He's being real fair on his asking price too. The biggest headache would be finding that sg unit for that puny rear. Personally I scrapped 2 and gave away 2 other 7-1/4's about a year ago because I got tired of tripping on them! They were good functional rears, too) Went with an 8-1/4 for my car. But if you must use the 7-1/4, mopar_nocar's parts stash is a real good start even if he doesn't have everything you need, you're that much ahead.
Author:  mopar_nocar [ Mon Dec 05, 2005 1:11 pm ]
Post subject: 
don,

thanks for the vote of confindence.

shipped the gears out today.

sorry about not knowing there was no 8.25 in early a-bodies. most of my a-bodies have been either 74s or older have had other rears that i installed (a 72 with a b-body 8.75, a 69 with a 8.25, a 74 with a Ford 8") etc.

that being said, the one i pulled from the 74 to put in the 8" looks to be exactly like the 7.25 in my 65 b-cuda. (they were at one point sitting side by side) i even used the springs off the 74 on my b-cuda.

sb
Author:  zedpapa [ Tue Dec 06, 2005 8:56 am ]
Post subject:  8.25
keep in mind that when putting in the 8.25, you need to shorten the driveshaft about an inch and a half. good time to have it balanced, too.

zedpapa
Author:  zedpapa [ Tue Dec 06, 2005 8:56 am ]
Post subject:  8.25
keep in mind that when putting in the 8.25, you need to shorten the driveshaft about an inch and a half. good time to have it balanced, too.

zedpapa
Author:  mopar_nocar [ Tue Dec 06, 2005 9:39 am ]
Post subject: 
good point.

i don't know if there is any difference in the rear u-joints on the early a-bodies.

sb


sb
Author:  featherduster76 [ Tue Feb 21, 2006 6:05 pm ]
Post subject: 
I was under the impression that an 8.25 was a bolt in job from a 7.25-
as in not having to shorten the driveshaft>>?? correct me if Im wrong here??? I heard you definetly had to shorten the driveshaft when swapping
to an 8.75....
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