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Discussion Starter · #1 · (Edited)
This is more a tale of caution to those that haven't gone through this.

For an 8.2 Rear end, you will find that you are equipped with a 1.4" internal diameter (ID) axle bearing and associated axle journal, or a 1.6" ID axle bearing and associated axle journal.

Measure first, buy later. The on-line shops (Jegs, Summit, etc..) won't clue you into this.

As a reference:
If you need the 1.4" - look into the Yukon YA-G1255804-SH
If you need the 1.6" - look into the Moser A102811

I haven't found a Axle bearing sets that match up for a 1.4" ID yet, FYI.
 

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Discussion Starter · #2 ·
... and the flange on my 8.2 rear-end measures out for a C-10 Truck - also matches the Bearing size. I've read that this was used for Impalas as well, but it sounds like there are a few flange options as well. Be sure to identify the flange when spec'ing out your add on parts. Here is what I'm dealing with:

Rectangle Font Circle Parallel Number


Verses, what all the on-line parts tool sites are telling me I need:

Rectangle Automotive lighting Motor vehicle Font Circle
 

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Discussion Starter · #3 ·
This just keeps getting better, but, working on old cars is part archaeology, with a touch of McGuyver-ing.

So while my flange is most def a C-10 flange, my axle offset with the new Yukon differential is 2.53, as opposed to 2.42. To mount a Wilwood disc brake kit, that is too much of a difference - since the Wilwood mounts come with their own spacers welded in for the 2.42 offset.

I slid the old axles in,and used the old c-clips, and I'm still coming up with 2.53. The backlash is dead on (.6) so it seems like the beefy new posi carrier has added .11 to the axle offset.

Isn't this fun? :-D

So now, I have to find a reputable rear brake kit that can work with this new tolerance, or find a modern rear disc kit, or weigh the option of grinding down the Wilwood kit to fit.

I'll but doing another search to see if anyone else has hit this condition before - but if anyone has any bright idea, feel free to drop them in here! Cheers!
 

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Discussion Starter · #4 ·
I have faith that come poor sap with a mid-year build of a 1968 Custom Cruiser will find this monologue useful, so I will continue to update my tale of discovery and enlightenment :)

So I have confirmed that mid-way through the 68 build year, Chevy swapped over to using C-10 flanges. Wilwood Brakes isn't aware of this by the way, and most on-line parts vendors aren't either. It's in-line with my discovery that the 68 is almost a lost year when it comes to the parts market. Regardless, if you run the measurements, their C-10 kits will work, unless you've gotten new axles. Between the thicker axle flange, and the beefier C-Clip flange on the far end on a set of Moser Axles, you will push the Axle offset .113", which is outside of the 2.41"-2.47" tolerance of the Wilwood brakes.

The best thing about getting Wilwoods vs Right Stuff brakes is that they are designed for the vehicle they work with inside of a tolerance. The Right Stuff kits, and most of the single pot/piston Cadillac replica brake kits that go for half the cost, use a lot of spacers to fit a lot of different models - and as such typically sacrifice mechanical quality in mounting, and invite a lot of grinding and fulcrum modification when things don't perfectly match up.

I've got a set of Right Stuff Rears, and was going to try to use them, however between the sketchy rear bracket mounting, and the fact they can't handle a beefier axle (flange tolerances wise) I decided to go premium. In all cases (Wilwood / Baer / Top-end CC / etc) these vendors don't quite meet the measurements of a mid-year run 68 Impala C-10 axle offset.

Here is where the solution comes in: What Right Stuff does sell, is a Bracket kit (CMB82) that includes a pair of C-10 bracket spacers that lay on the enitrity of the flange... that measure .113". It's $100 - but since I don't have the stamping and machining tools, it's a god-send. Once I get the pinion depth dialed into my rebuilt rear-end, I'll post some pictures.
 

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Discussion Starter · #6 ·
Right on man, thanks! - I'll see if I can't run a double check through him. I'm 99% sure I've gotten this beast slayed at this point - and while it's been a little frustrating, and I'd rather be wrenching than reading and measuring, I sorta have enjoyed the history study to bring it all together. Despite killer production numbers, the 68 and 69 Impalas have a freaking crater size hole in parts and tribal knowledge.
 
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