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Old 01-31-2016, 06:17 PM
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ncbeefjerky ncbeefjerky is offline
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Smile replaceing 7.5 in 79 El

I would like any advise or help replacing my my 2:42 7.5 rear end. From what I have read the 7.5 is not worth rebuilding, I am running a 350 with a mild cam and 700R4 and 2800 stall, I would like a 336 or 350 gear with posi. Most of the post that I see are years old I do not want a ford rear no serious racing just some thing dependable and a better low end. Unable to find a 8.5 in my area I have a lot of wants and small wallet and any help would be great.
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Old 01-31-2016, 09:29 PM
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Bolt in 9" is your best bet or the 8.8 swap, and if you can find a fair priced 64-up 12 bolt, those are a good choice also. I ran this one in a cutlass I had http://www.speedwaymotors.com/Winter...kets,4856.html and I have this one ready to go in my wagon http://www.quickperformance.com/9-Fo...7_p_20384.html
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Old 02-02-2016, 01:14 PM
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DOUG213XRJ DOUG213XRJ is offline
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I would run a New or used 7.5/8 Auburn posi with 3.42 gears in the stock 7.5 rear end. Look on ebay.


Doug
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Old 02-02-2016, 06:25 PM
melloelky melloelky is offline
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^i had good luck with that years ago,i bought a rear end locally from a monte ss,thought it was a 7.5 turned out to be a 7.5/8.put a powertrax in place of the spider gears.it was already 3:73's and didn't know how to set up a posi or anything to do with that stuff and it worked great.i beat on it for a few years with et streets with no problems.it was on the cheap too
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Old 02-03-2016, 02:32 AM
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monte ss496 monte ss496 is offline
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Your 7.5 will survive for awhile as long as you stay away from slicks but you are right in not rebuilding it..
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Old 02-03-2016, 06:41 AM
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Quote:
Originally Posted by ncbeefjerky View Post
I would like any advise or help replacing my my 2:42 7.5 rear end. From what I have read the 7.5 is not worth rebuilding, I am running a 350 with a mild cam and 700R4 and 2800 stall, I would like a 336 or 350 gear with posi. Most of the post that I see are years old I do not want a ford rear no serious racing just some thing dependable and a better low end. Unable to find a 8.5 in my area I have a lot of wants and small wallet and any help would be great.
If and when your rear diff explodes under its own weight, you really should consider the QP 9". It is hands down the most inexpensive new/rebuilt rear you can get for the money. I took about three months pricing diffs and even bone yards (if they could even get one) wanted 500 plus, then I was looking at a rebuild shop at another 2000. Then what if you don't like the gear ratio? Now you get to do it all over again. A 9" gear change is super simple and on a bench. Now pulling the 35+ lbs carrier out 100 times just to get the back lash right. Not even mentioning the pinion gear..... 9" is the way to go all day and it bolts in the car!

I built mine just the way I wanted it, 3:70 gears, rear wilwood disc brakes, Yukon third member, Eaton truetrac posi, big axles, upgraded seal ends, blah blah blah all shipped to my front door for just over 3k. That's just my opinion.
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Old 02-15-2016, 09:55 AM
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ncbeefjerky ncbeefjerky is offline
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Thanks fro the reply's, just can not get my head around the ford rear end, I have heard some thing about using the rear from an S10 and what should I look for in a 12 bolt ran thous in my 409 days any information is helpful and appreciated.
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Old 02-16-2016, 06:47 AM
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There is a 12 bolt on here for sale unless he sold it. It is out of a Chevelle. The only thing I know that is different is the upper or the lower control arm mounts is slightly different. You will need a set of adjustable arms to correct (so I've heard) and the they are a bit wider like an inch or two. Not sure the details. I bought a custom 9" from QP, so I don't really know.
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Old 02-16-2016, 05:16 PM
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monte ss496 monte ss496 is offline
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I still have the 12 bolt for sale and it includes the arms to swap it in.. any questions please pm me
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