rear end identification

[tarpit]

Im hopeing one of you can help me.
Im haveing the hardest time finding out about the rearends they used for my 69 cuda fast back.
I know its an 8 and a quarter with 3.23 gears but i have another one in a 68 that acts like a posi traction.
Lights um up all the way down the street.
Im thinking of swaping the rear end thats in my 69 for the one that came out of the 68.
My question is did chrysler make a positraction in the late 60`s for these cars /,and if they did how do you identify it?
Or is this what they called a limited slip differential???
Thanks any help would be over whelmingly appreciated!
Machin head Dan

 

[Burntorange70]

Positraction is chevy stuff. LOL
You are right it would be called a limited slip or like I like to call them a sure grip. The best way to tell is to jack the rear of the car up and turn one wheel. If the other wheel turns the same way it is a sure grip. If it turns the oposit way it is an open diff.

Good luck.

 

[cosgig]

tarpit, are you sure that it is an 8 1/4?? The 8 1/4 did not come out until 72 or 73, up until then it was either 7 1/4 or an 8 3/4. The 8 3/4 is a front load center section and the 7 1/4 is a rear cover unit, which I highly doubt would be a suregrip, although they did make a suregrip for 7 1/4. If it is an 8 1/4 it is a transplanted unit, but it was also available with a suregrip unit. Take Burntorange's instruction and find out if either is a suregrip before you swap anything out. If the one in the 68 is a suregrip, the whole unit is a bolt in, or if they are both 8 3/4, the center section can be swapped easily. Good luck! Geof

 

[cuda65vpt]

memike posted a nice one sheet rearend spotter the other day.

 

[Longgone]

This will help identify what differential you have. Burnts instructions can help you find out if it`s a sure-grip or not.

 

[cosgig]

This will help identify what differential you have. Burnts instructions can help you find out if it`s a sure-grip or not.

Man, I love that axle spotters guide, and thanks for posting it, Longgone. I would have referenced it myself but I wouldn't know how to post it!!! My kid would probably know though!!!LOL!! Geof

 

[Longgone]

Yeah, the kids got it all over us when it comes to computers.

 

[Burntorange70]

Hey nice rear end guide! I am going to save that. It will come in handy.

 

[JoseyWales]

I dont want to hijack this thread but I have a rear end question also, anyone know the width (wheel mounting plate to wheel mounting plate) of an a-body rear?

 

[cosgig]

I dont want to hijack this thread but I have a rear end question also, anyone know the width (wheel mounting plate to wheel mounting plate) of an a-body rear?

From the inside to the inside of the brake backing plates I believe they measure 50 3/4". I think if i'm not mistaken, longgone has another page of that rear end spotters guide that includes all of the measurements of all of the rearends for all Mopar cars. Maybe if you talk nice to him ( or maybe dirty) he'll post the measurement page. Or just P.M. him, I think it's him that posted it before in it's complete form. Geof

 

[demon seed]

This what you're looking for? http://www.moparts.org/Tech/Archive/axle/17.html

Terry