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Discussion Starter · #1 ·
I have a 1969 Nova with a 10 bolt 8.2" rear end. I have in my garage a complete rear end that is a 10 bolt 8.5" rear end. The 8.5 is a posi and the 8.2 in my nova isn't. I wanted to just swap the internals from the 8.5 posi to the 8.2 and use a 3.73 ring gear and pinion. Will this work? And what would i need to do to make it work? The only reason i don't swap the whole dif is that the 8.5 is 1 inch wider in overall length. Also i have a 350 with a th350 2000 stall convertor. Is a 3.73 a good choice. I want moderate between high performance and streetability. Thanks for any help.

Matt
 

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:D



I bought a NEW 1969 Nova SS.......in 1969. It was a 396 - 375 horse 4 speed car with the aluminum head option. ...........it was BRISK :D :D

I do not believe you can use the 8.5 in the 8.2

I think 3.55 is as high as your carrier will go.

A 57 - 59 Ford 9 inch is almost a bolt in...........and parts are easy to find.

:thumbup:
 

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I'm almost positive the two rears' insides are not interchangeable.

If the 8.5 would bolt up, why not just put it in. The difference would only be 1/2" on each side. Barring tire clearance issues, that doesn't seem to be a problem.

Your 2.73 is a 2-Series carrier. A 3-Series carrier starts at 3.08. To go to a lower (higher numbered) rear gear you'd have to either buy a spacer or buy gears made to fit a 2-Series.
 

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Discussion Starter · #5 ·
i did some more measuring on the 8.5 and the mounting areas are off about 2 inches and it is 1 and 3/4 inches longer than the 8.2 overall. If i were to buy a posi unit from eaton would it fit? Just have to set it up? Also would it be worth looking for a 12 bolt? I do'nt think that my horsepower will require one. I plan to when i am all done with my motor to be around 500 HP. Thanks again.

Matt
 

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The "series" break points are different from one rear end design to another. The 8.2 changes between 2.73 & 3.08, but the 8.5 changes between 2.56 & 2.73. Best bet if you're going to get a posi carrier anyway is to pick what gear ratio you want, then get a posi carrier of the series that matches your new gearset, then get the whole mess installed at the same time.

You could also get an 8.5 rear (almost as strong as a 12-bolt) from a '72-'79 Nova & use the 8.5 posi unit in it. Your driveshaft would probably need to be shortened a little, since the 8.5 is longer from axle to snout than the 8.2. '73-'79 Novas (and '72 SS's) all had multileaf rear springs, so if you can't find a '72 monoleaf unit, you'd need some type of spacer blocks to take up the extra space, or multileaf springs. Not all later Novas had 8.5's, some had 7.5's. Here's ID info:
http://tech.oldsgmail.com/axle_ident.html
 
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