I've got a 12 bolt out of a 70 grand prix ,wondering if it will fit into a
69 chevelle without too much dickin around?


ROD AND ROLL ;)

It will bolt up if you swap the whole rear end. Internals on BOP & Chevy rears are different.

As mentioned in a topic I asked about a 10-bolt oldsmobile, the brakes mey be different, and check to see the the pinion is in the same location, so that your existing driveshaft can be used w/o modification. Good luck, and post results!

Some 70-72 Pontiac's with BB got Chevy 12 bolt rears...Check the axle code stamp forward side of passenger tube and post it.

Edit: I show the 70-72 codes for the Chevy 12 bolts in Pontiacs are:

3.07 WT standard, XT Posi
3.31 WU standard, XU Posi
3.55 WV standard, XV Posi

Rene
66_Malibu

The 70-72 Pontiacs that had a 455 got a 12 bolt. I do believe they were the same as Chevy 12 bolts. There is no BB or SB in the Pontiac engine family. All blocks from a 326-455 had exactly the same external dimensions, with some variations regarding engine mounts.

Andrew