66 Tempest 12-bolt rear end?

Hi Folks,
First time poster here. I just bought a 66 Tempest post car for a project. PHS says it was a Turquoise/Turquoise 6-cylinder car from the factory but it has a correctly-coded 4-barrel 326 in it now, plus a complete Black Lemans bucket seat interior with a 2-speed automatic. Came with a radio and thats it! Anyway, it has a 12-bolt rear end in it and I was wondering if that is the same as a Chevy 12-bolt, which would be a GREAT thing!

Thanks for any help you can give me.
Mark in Michigan  

Welcome to the Forum you will find good information and good people here, as-well-as good answers.  A lot of parts are interchangeable but my Interchange Manual only goes back to 73 so I am not certain if they were the same in 66 but they should be.

BTW the 326 isn't a bad motor but I always loved the six, in fact, my first new car was a 66 - 67 tempest with the 207 Hp engine.  Have fun with your restoration and read the past Post   Article 1 – Projects, a few tips


http://forums.highperformancepontiac.com/70/8552763/the-general-discussion/article-1-projects-a-few-tips/index.html  

There were 2 A body rear ends that had a 12 bolt cover, the Chevy 12 bolt and the olds 12 bolt. The olds has a round cover with a symmetrical bolt pattern and is essentially a gm 8.5". Chevy 12 bolt has more of an irregular bolt pattern.  

If I remember right, the cover is symetrical, so that points to the 8.5" Olds rear end. Does anyone know parts availability and how strong these are compared to the 8.875" Chevy 12-bolt? I definitely want rear disc brakes, posi etc. When I am done with this car (10 years from now probably LOL) I want to have way too much horsepower and windows to shake when I drive by. Thanks.  

I could be wrong, but i remember correctly  the olds 12 bolt is a weaker rear end vs the chevy 12 bolt...  

That is true  

Welcome to HPP Mark.  
Horsepower sells engines and torque wins races

Unfortunately the chevy s are cheaper to service.  Save your mony and buy a complete rear with discs and locker from aftermarket and sell that one.  Worth about 350- 450.  New loaded rear with gears locker and discs should be about 3000.  After labor to pay a shop to build yours it will almost reach that price.  
Carlos
70 Lemans(GTO Clone),406,Solid Cam 218 single pattern, 105 LSA
Serious Hobbyist

I was hoping to luck out, but that's the answer I was expecting :-(
Luckily there are a lot of choices when the time comes.