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difference between 7.5 and 8.5 10 bolt

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Old Sep 25, 2007 | 09:23 PM
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Default difference between 7.5 and 8.5 10 bolt

difference between 7.5 and 8.5 10 bolt 3 series carrier. I have and 1998 a4 z28 the door index is GU5. but my question is that which is in my car.
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Old Sep 25, 2007 | 09:32 PM
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7.5 you have..... im not sure but i think the 8.5s in camaros went away in 1982.
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Old Sep 27, 2007 | 07:23 PM
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the difference is 1 inch! LOL
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Old Sep 27, 2007 | 07:35 PM
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GU5 = 3.23
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Old Sep 27, 2007 | 08:45 PM
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Originally Posted by JFM-jr
GU5 = 3.23
GU5 = 3.23, 7.5/7.625 (they are the same) a 1998 F-Body rear is not an 8.5.
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Old Sep 27, 2007 | 09:53 PM
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Originally Posted by LS1crazy01
the difference is 1 inch! LOL
That was my first thought when I saw the post.
Of course, I have been called a smartass before, for some strange reason.
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Old Sep 28, 2007 | 12:39 PM
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7.5" cover is sort of a square oval, the cover on a 8.5" is rounder.
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Old Sep 29, 2007 | 07:06 PM
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Originally Posted by Horsepwraddict
7.5" cover is sort of a square oval, the cover on a 8.5" is rounder.
yup
and the 8.5 has larger carrier bearings
larger carrier
larger ring and pinion
30 spline axles

im sure there is more but thats all i can rememebr off the top of my head.

i love the 8.5 in my s10
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Old Sep 29, 2007 | 07:36 PM
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Not to mention the pinion shaft and associated bearings are measurably larger, which is a key point to its strength.
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Old Sep 30, 2007 | 05:35 AM
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GM did the aftermarket a huge favor by installing the puny 7.5 rear in these cars! Bob
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