I have a 10 bolt corporate, SD code 3.08 posi gears
that I wanted to swap into a rear out of a 69 cutlass code
R2 2.56 peg leg. The 69 is the 12 bolt housed unit.
Is this possible using the axels of the 69.
Basically unbolting, sliding axels out a bit, placing the posi pumpkin
in, and bolting it back together? Because that would be too easy.

 

Not happening. No parts interchange.

 

Sorry Adam, as Dave said they're two different animals and the parts won't interchange. The corporate one will fit under your car, although I'm not sure if the driveline length would need to be changed or not. So you could swap the whole rear end, which would give you more options for gears and parts including a posi carrier If it were me that's what I'd do, but first I'd put in a posi carrier with the gears you want and stash the original rear end under a workbench somewhere. On a 442 I hesitate to make changes that cannot easily be swapped back, that's why I'd keep the factory rear end. On a Cutlass I wouldn't think twice. John

 

Thanks for the comments guys.
The 10 bolt 3.08 came with a bunch
of parts, but no brakes, drums etc.
The 12 bolt peg-leg is a complete unit.
It was a nice thought though. My 442
has its original 3.23 SF code posi. I have a 200 4R
to rebuild for it out of a grand nat.
I am hoping that will be a nice package for the
street and hiway, if I ever get the silly thing finished.

 

You are aware that the "12 bolt" out of the 69 really isn't a 12-bolt, aren't you? That's a Type O axle, and despite having twelve bolts on the cover, there are only ten bolts holding an 8.5" ring gear. Your corporate ten bolt axle also has an 8.5" ring gear, however no parts interchange between the two axles, as notes. Not only that, but the pinion flange-to-axle centerline distance is different between the two housings, so even the driveshaft is different.