Where to buy 12 bolt gears and stuff?

Hi guys;
What will be needed for the following....
I have a 12 bolt rear from a 71 Monte Carlo in my 70 GS. It curently has 4:10's in it.
Where can I get the parts for making it into a 3:31 gear ratio with posi? Would I need a 3 series carrier, posi, and 3:31 or so gears? Am I missing anything?
Thank's;
Mike

 

Get new gears and an Eaton posi unit. You can get them from Jegs or Summit. You can also contact some rear axle builders in your area to see what they have. Do NOT use Richmond gears, poor quality.

 

You can't buy 3.31:1 gearsets new anymore. They'll have to be used. Contact OPH.

 

Try www.gearsareus.com.

 

Thanks for the help. I am just learning about the rear ends on cars and needed some direction.
Thank's;
Mike

 

12 bolt stuff....

I can help if you need stuff or the whole rear built. I have used sets of 3.31...they are pricey since they are the original SS gears from chevy cars. Chevelle Monte Carlos and el caminos. I have new and used posis too.
If you are at all interested let me know or just need some help. Jim

 

Thanks Jim.
Mike