I have a 1969 olds cutlass s my question is I have a rear end that has a 12 bolt cover and 10 bolt rear end o style. I guess they call it a gm 8.5 what I am trying to do is find a way to make it limited slip or posi tracktion. I dont know the size of gears I can put in it 308s or 373s Im hoping you guys can help me out. Dont got much money so I have to do it right the first time. Thank you. sorry if my spelling is bad

 

You have the "Type O" rear, not the corporate 8.5" that was used by Olds beginning in 1971; it had a 10 bolt cover and ring gear attachment. The performance ratio carrier was for 3.42 and higher numbers. Limited performance parts are available; check Brian Trick (507Olds) on this board.

 

It's been about 10 years ago, but I put a Alburn unit in my 70. Not sure they still make, but I would check with them.

 

I know i cant do much with the rear end i have . so what can i do go chevy or ford rear end? To get the lower gears i know you guys say NO !!! BUT IT SOUNDS LIKE I DONT HAVE MUCH TO WORK WITH. THAT IS WHY I AM ASKING FOR HELP. I called arownd and everybody said the samething change the rear end that you cant get eanything for them .

 

I have 70 that had a 12 bolt type O rearend with an open carrier. I bought a posi unit from a guy on this board. monzaz. He has a website as well.

www.jdrace.com

 

Do you know his web site ? I dont want to join another car club . Or phone # thank you

 

www.jdrace.com

 

I'm pretty sure you can put a '71 or later type rear end in your car with little/no problem. They have a 10 bolt cover, 8.5 ring gear, & parts are much easier to get than for the original '70 type. I can supply you with a rear end core to be rebuilt, or Brian trick(507olds) I believe can supply you with anything you need.
Good luck.